ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Oxford University Press  (75,518)
  • American Institute of Physics (AIP)  (49,884)
  • International Union of Crystallography  (45,103)
  • American Association for the Advancement of Science (AAAS)
  • American Meteorological Society
  • 2005-2009  (97,930)
  • 1995-1999  (109,268)
Collection
Keywords
Publisher
Years
Year
  • 1
    Unknown
    Inorganic polymers (2005)
    New York : Oxford University Press
    Details
    Keywords: Inorganic polymers.
    Pages: xiv, 338 p.
    Edition: 2nd ed
    ISBN: 1-423-71993-X
    URL: http://www.netLibrary.com/urlapi.asp?action=summary&v=1&bookid=138141
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    E-Book (German National Licenses)
  • 2
    facet.materialart.
    Unknown
    Aegean Sea Water Masses during the Early Stages of the Eastern Mediterranean Climatic Transient (2007)
    American Meteorological Society
    Details
    Publication Date: 2021-06-08
    Description: The Aegean water masses and circulation structure are studied via two large-scale surveys performed during the late winters of 1988 and 1990 by the R/V Yakov Gakkel of the former Soviet Union. The analysis of these data sheds light on the mechanisms of water mass formation in the Aegean Sea that triggered the outflow of Cretan Deep Water (CDW) from the Cretan Sea into the abyssal basins of the eastern Mediterranean Sea (the so-called Eastern Mediterranean Transient). It is found that the central Aegean Basin is the site of the formation of Aegean Intermediate Water, which slides southward and, depending on their density, renews either the intermediate or the deep water of the Cretan Sea. During the winter of 1988, the Cretan Sea waters were renewed mainly at intermediate levels, while during the winter of 1990 it was mainly the volume of CDW that increased. This Aegean water mass redistribution and formation process in 1990 differed from that in 1988 in two major aspects: (i) during the winter of 1990 the position of the front between the Black Sea Water and the Levantine Surface Water was displaced farther north than during the winter of 1988 and (ii) heavier waters were formed in 1990 as a result of enhanced lateral advection of salty Levantine Surface Water that enriched the intermediate waters with salt. In 1990 the 29.2 isopycnal rose to the surface of the central basin and a large volume of CDW filled the Cretan Basin. It is found that, already in 1988, the 29.2 isopycnal surface, which we assume is the lowest density of the CDW, was shallower than the Kassos Strait sill and thus CDW egressed into the Eastern Mediterranean.
    Description: Published
    Description: 1841-1859
    Description: JCR Journal
    Description: reserved
    Keywords: Aegean Sea ; Water Masses ; 03. Hydrosphere::03.03. Physical::03.03.03. Interannual-to-decadal ocean variability
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 3
    facet.materialart.
    Unknown
    Gulf Stream Variability in Five Oceanic General Circulation Models (2008)
    American Meteorological Society
    Details
    Publication Date: 2021-06-01
    Description: Five non-eddy-resolving oceanic general circulation models driven by atmospheric fluxes derived from the NCEP reanalysis are used to investigate the link between the Gulf Stream (GS) variability, the atmospheric circulation, and the Atlantic meridional overturning circulation (AMOC). Despite the limited model resolution, the temperature at the 200-m depth along the mean GS axis behaves similarly in most models to that observed, and it is also well correlated with the North Atlantic Oscillation (NAO), indicating that a northward (southward) GS shift lags a positive (negative) NAO phase by 0–2 yr. The northward shift is accompanied by an increase in the GS transport, and conversely the southward shift with a decrease in the GS transport. Two dominant time scales appear in the response of the GS transport to the NAO forcing: a fast time scale (less than 1 month) for the barotropic component, and a slower one (about 2 yr) for the baroclinic component. In addition, the two components are weakly coupled. The GS response seems broadly consistent with a linear adjustment to the changes in the wind stress curl, and evidence for baroclinic Rossby wave propagation is found in the southern part of the subtropical gyre. However, the GS shifts are also affected by basin-scale changes in the oceanic conditions, and they are well correlated in most models with the changes in the AMOC. A larger AMOC is found when the GS is stronger and displaced northward, and a higher correlation is found when the observed changes of the GS position are used in the comparison. The relation between the GS and the AMOC could be explained by the inherent coupling between the thermohaline and the wind-driven circulation, or by the NAO variability driving them on similar time scales in the models.
    Description: This research was supported by the PREDICATE project of the European Community, and for M. Bentsen by the Research Council of Norway through RegClim, NOClim, and the Programme of Supercomputing.
    Description: Published
    Description: 2119–2135
    Description: 3.7. Dinamica del clima e dell'oceano
    Description: JCR Journal
    Description: reserved
    Keywords: ocean modelling ; gulf stream variability ; 03. Hydrosphere::03.01. General::03.01.03. Global climate models
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 4
    facet.materialart.
    Unknown
    Effects of Land-Surface-Vegetation on theboreal summer surface climate of a GCM (2007)
    American Meteorological Society
    Details
    Publication Date: 2020-11-19
    Description: A land surface model (LSM) has been included in the ECMWF Hamburg version 4 (ECHAM4) atmospheric general circulation model (AGCM). The LSM is an early version of the Organizing Carbon and Hydrology in Dynamic Ecosystems (ORCHIDEE) and it replaces the simple land surface scheme previously included in ECHAM4. The purpose of this paper is to document how a more exhaustive consideration of the land surface–vegetation processes affects the simulated boreal summer surface climate. To investigate the impacts on the simulated climate, different sets of Atmospheric Model Intercomparison Project (AMIP)-type simulations have been performed with ECHAM4 alone and with the AGCM coupled with ORCHIDEE. Furthermore, to assess the effects of the increase in horizontal resolution the coupling of ECHAM4 with the LSM has been implemented at different horizontal resolutions. The analysis reveals that the LSM has large effects on the simulated boreal summer surface climate of the atmospheric model. Considerable impacts are found in the surface energy balance due to changes in the surface latent heat fluxes over tropical and midlatitude areas covered with vegetation. Rainfall and atmospheric circulation are substantially affected by these changes. In particular, increased precipitation is found over evergreen and summergreen vegetated areas. Because of the socioeconomical relevance, particular attention has been devoted to the Indian summer monsoon (ISM) region. The results of this study indicate that precipitation over the Indian subcontinent is better simulated with the coupled ECHAM4–ORCHIDEE model compared to the atmospheric model alone.
    Description: Published
    Description: 255–278
    Description: 3.7. Dinamica del clima e dell'oceano
    Description: JCR Journal
    Description: partially_open
    Keywords: Land Atmosphere interactions ; Global climate models ; 01. Atmosphere::01.01. Atmosphere::01.01.02. Climate
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 5
    facet.materialart.
    Unknown
    Using Temperature–Salinity Relations in a Global Ocean Implementation of a Multivariate Data Assimilation Scheme (2008)
    American Meteorological Society
    Details
    Publication Date: 2017-04-04
    Description: In this paper results from the application of an ocean data assimilation (ODA) system, combining a multivariate reduced-order optimal interpolator (OI) scheme with a global ocean general circulation model (OGCM), are described. The present ODA system, designed to assimilate in situ temperature and salinity observations, has been used to produce ocean reanalyses for the 1962–2001 period. The impact of assimilating observed hydrographic data on the ocean mean state and temporal variability is evaluated. A special focus of this work is on the ODA system skill in reproducing a realistic ocean salinity state. Results from a hierarchy of different salinity reanalyses, using varying combinations of assimilated data and background error covariance structures, are described. The impact of the space and time resolution of the background error covariance parameterization on salinity is addressed.
    Description: This work has been funded by the ENACT Project (Contract EVK2-CT2001-00117) for A. Bellucci and P. Di Pietro, and partially by the ENSEMBLES Project (Contract GOCE-CT-2003-505539) for A. Bellucci.
    Description: Published
    Description: 3785-3807
    Description: 3.7. Dinamica del clima e dell'oceano
    Description: JCR Journal
    Description: reserved
    Keywords: ocean modelling ; data assimilation ; reanalysis ; upper ocean variability ; temperature ; Salinity ; 03. Hydrosphere::03.01. General::03.01.04. Ocean data assimilation and reanalysis
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 6
    facet.materialart.
    Unknown
    Atmospheric horizontal resolution affects tropical climate variability in coupled models (2008)
    American Meteorological Society
    Details
    Publication Date: 2017-04-04
    Description: The effect of horizontal resolution on tropical variability is investigated within the modified SINTEX model, SINTEX-F, developed jointly at INGV, IPSL and at the Frontier Research System. The horizontal resolutions T30 and T106 are investigated in terms of the coupling characteristics, frequency and variability of the tropical ocean-atmosphere interactions. It appears that the T106 resolution is generally beneficial even if it does not eliminate all the major systematic errors of the coupled model. There is an excessive shift west of the cold tongue and ENSO variability, and high resolution has also a somewhat negative impact to the variability in the East Indian Ocean. A dominant two-year peak for the NINO3 variabilty in the T30 model is moderated in the T106 as it shifts to longer time scale. At high resolution new processes come into play, as the coupling of tropical instability waves, the resolution of coastal flows at the Pacific Mexican coasts and improved coastal forcing along the coast of South America. The delayed oscillator seems the main mechanism that generates the interannual variability in both models, but the models realize it in different ways. In the T30 model it is confined close to the equator, involving relatively fast equatorial and near-equatorial modes, in the high resolution, it involves a wider latitudinal region and slower waves. It is speculated that the extent of the region that is involved in the interannual variability may be linked to the time scale of the variability itself.
    Description: This research was partially supported by the Italy–USA Cooperation Program of the Italian Ministry of Environment and by the EU projects ENSEMBLES and DYNAMITE.
    Description: Published
    Description: 730-750
    Description: 3.7. Dinamica del clima e dell'oceano
    Description: JCR Journal
    Description: reserved
    Keywords: coupled models ; tropical variability ; ENSO system ; 03. Hydrosphere::03.01. General::03.01.03. Global climate models
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 7
    facet.materialart.
    Unknown
    The influence of Tropical Indian Ocean SST on the Indian summer monsoon (2007)
    American Meteorological Society
    Details
    Publication Date: 2017-04-04
    Description: The Indian Summer Monsoon (ISM) is one of the main components of the Asian summer monsoon. It is well known that one of the starting mechanisms of a summer monsoon is the thermal contrast between land and ocean and that sea surface temperature (SST) and moisture are crucial factors for its evolution and intensity. The Indian Ocean, therefore, may play a very important role in the generation and evolution of the ISM itself. A coupled general circulation model, implemented with a high resolution atmospheric component, appears to be able to simulate the Indian summer monsoon in a realistic way. In particular, the features of the simulated ISM variability are similar to the observations. In this study, the relationships between ISM and Tropical Indian Ocean (TIO) SST anomalies are investigated, as well as the ability of the coupled model to capture those connections. The recent discovery of the Indian Ocean Dipole Mode (IODM) may suggest new perspectives in the relationship between ISM and TIO SST. A new statistical technique, the Coupled Manifold, is used to investigate the TIO SST variability and its relation with the Tropical Pacific Ocean (TPO). The analysis shows that the SST variability in the TIO contains a significant portion that is independent from the TPO variability. The same technique is used to estimate the amount of Indian rainfall variability that can be explained by the Tropical Indian Ocean SST. Indian Ocean SST anomalies are separated in a part remotely forced from the Tropical Pacific Ocean variability and a part independent from that. The relationships between the two SSTA components and the Indian monsoon variability are then investigated in detail.
    Description: Published
    Description: 3083-3105
    Description: 3.7. Dinamica del clima e dell'oceano
    Description: JCR Journal
    Description: reserved
    Keywords: Indian Ocean ; monsoon ; 01. Atmosphere::01.01. Atmosphere::01.01.02. Climate
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 8
    facet.materialart.
    Unknown
    Marine Environment and Security for the European Area (MERSEA) - Towards operational oceanography (2007)
    American Meteorological Society
    Details
    Publication Date: 2017-04-04
    Description: An assessment of the present European operational marine monitoring and forecasting systems shows how observations, atmospheric forcing fields and ocean models combine to make useful oceanographic products possible.
    Description: Published
    Description: 1081-1090
    Description: open
    Keywords: MARINE ENVIRONMENT ; 03. Hydrosphere::03.01. General::03.01.05. Operational oceanography
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 9
    facet.materialart.
    Unknown
    Interannual to Decadal Climate Predictability in the North Atlantic: A Multi-Model-Ensemble Study (2007)
    American Meteorological Society
    Details
    Publication Date: 2017-04-04
    Description: Ensemble experiments are performed with five coupled atmosphere–ocean models to investigate the potential for initial-value climate forecasts on interannual to decadal time scales. Experiments are started from similar model-generated initial states, and common diagnostics of predictability are used. We find that variations in the ocean meridional overturning circulation (MOC) are potentially predictable on interannual to decadal time scales, a more consistent picture of the surface temperature impact of decadal variations in the MOC is now apparent, and variations of surface air temperatures in the North Atlantic Ocean are also potentially predictable on interannual to decadal time scales, albeit with potential skill levels that are less than those seen for MOC variations. This intercomparison represents a step forward in assessing the robustness of model estimates of potential skill and is a prerequisite for the development of any operational forecasting system.
    Description: Published
    Description: 1195-1203
    Description: JCR Journal
    Description: reserved
    Keywords: Decadal Climate ; North Atlantic ; 03. Hydrosphere::03.01. General::03.01.03. Global climate models ; 03. Hydrosphere::03.02. Hydrology::03.02.05. Models and Forecasts ; 03. Hydrosphere::03.03. Physical::03.03.03. Interannual-to-decadal ocean variability
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 10
    facet.materialart.
    Unknown
    Tropospheric Comparisons of Vaisala Radiosondes and Balloon-Borne Frost-Point and Lyman-α Hygrometers during the LAUTLOS-WAVVAP Experiment (2008)
    American Meteorological Society
    In:  EPIC3Journal of Atmospheric and Oceanic Technology, American Meteorological Society, 25(2), pp. 149-166, ISSN: 0739-0572
    Details
    Publication Date: 2019-07-17
    Description: The accuracy of all types of Vaisala radiosondes and two types of Snow White chilled-mirror hygrosondes was assessed in an intensive in situ comparison with reference hygrometers. Fourteen nighttime reference comparisons were performed to determine a working reference for the radiosonde comparisons. These showed that the night version of the Snow White agreed best with the references [i.e., the NOAA frost-point hygrometer (FPH) and University of Colorado cryogenic frost-point hygrometer (CFH)], but that the daytime version had severe problems with contamination in the humid upper troposphere. Since the RS92 performance was superior to the other radiosondes and to the day version of the Snow White, it was selected to be the working reference. According to the reference comparison, the RS92 has no bias in the mid- and lower troposphere, with deviations 〈±5% in relative humidity (RH). In the upper troposphere, the RS92 has a 5% RH wet bias, which is partly due to the RS92 time lag error and the termination of the heating cycle. It was shown that the time lag effects relating to Vaisala radiosondes can be corrected. Because these were nighttime comparisons, they can be considered to be free from solar radiation effects. Neither the radiosondes nor the Snow White succeeded in reproducing reference class hygrometer profiles in the stratosphere. According to the 29 radiosonde intercomparisons, the RS92 and the modified RS90 (FN) had the best mutual agreement and no bias. The disagreement is largest (〈±10% RH) at low temperatures (T ≪ −30°C), where the FN underestimated (overestimated) in high (low) ambient RH. In comparison with the RS92, the RS90 had a semilinearly increasing wet bias with decreasing temperature, where the bias was 10% RH at −60°C. The RS80-A suffers from a large temperature-dependent dry bias in high RH conditions, being over 30% RH at −60°C and 5% RH near 0°C. The RS80-A dry bias can be almost totally removed with the correction algorithm by Leiterer et al., which was chosen as the best available. The other approach tested tends to overcorrect in high RH conditions when T 〈 −50°C. For T 〉 −30°C it is ineffective and does not correct the RS80-A dry bias in high ambient RH.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 11
    facet.materialart.
    Unknown
    The Teleconnection between the Western Indian and the Western Pacific Oceans (2005)
    American Meteorological Society
    Details
    Publication Date: 2021-05-19
    Description: In this study we show a teleconnection pattern relating Outgoing Longwave Radiation (OLR) anomalies over the western Pacific Ocean and sea surface temperature anomalies (SSTA) over the western Indian Ocean over two seasons (Sept-Oct-Nov and Dec-Jan-Feb) at zero lag from observations and atmospheric general circulation model (AGCM) integrations. This teleconnection pattern suggests that a positive SSTA in Sept-Oct-Nov (SON) and Dec-Jan-Feb (DJF) seasons over the western Indian Ocean increases the contemporaneous positive OLR anomalies over the western Pacific Ocean. This teleconnection pattern is also simulated by the Center for Ocean-Land- Atmosphere studies (COLA) AGCM forced with observed SST’s. From the experimental COLA AGCM runs (wherein the Pacific Ocean SST variability is suppressed except for the climatological annual cycle) it is diagnosed that the interannual variability of OLR over the western Pacific Ocean persists because of this teleconnection. In relation to this teleconnection pattern it is shown that there is a significant linear response of the SON and DJF equatorial zonal wind anomaly over the Pacific Ocean to contemporaneous SSTA over the western Indian Ocean which is comparable to that of the eastern and western Pacific Oceans. The experimental AGCM runs clearly show that this response of the equatorial zonal wind anomaly to the western Indian Ocean forcing shifts westward towards the Indian Ocean in the absence of Pacific SST variability.
    Description: Published
    Keywords: Sea surface temperature ; Atmospheric conditions ; Teleconnections
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed , Article
    Format: 759939 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 12
    facet.materialart.
    Unknown
    The Role of the Land Surface Background State in Climate Predictability (2005)
    American Meteorological Society
    Details
    Publication Date: 2021-05-19
    Description: Skill in ensemble-mean dynamical seasonal climate hindcasts with a coupled land-atmosphere model and specified observed sea surface temperature is compared to that for long multi-decade integrations of the same model where the initial conditions are far removed from the seasons of validation. The evaluations are performed for surface temperature and compared among all seasons. Skill is found to be higher in the seasonal simulations than the multi-decadal integrations except during boreal winter. The higher skill is prominent even beyond the first month when the direct influence of the atmospheric initial state elevates model skill. Skill is generally found to be lowest during the winter season for the dynamical seasonal forecasts, equal to that of the long integrations, which show some of the highest skill during winter. The reason for the differences in skill during the non-winter months is attributed to the severe climate drift in the long simulations, manifest through errors in downward fluxes of water and energy over land and evident in soil wetness. The drift presses the land surface to extreme dry or wet states over much of the globe, into a range where there is little sensitivity of evaporation to fluctuations in soil moisture. Thus, the land-atmosphere feedback is suppressed, which appears to lessen the model’s ability to respond correctly over land to remote ocean temperature anomalies.
    Description: Center for Ocean-Land-Atmosphere Studies
    Description: Published
    Keywords: Atmosphere-ocean system
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed , Article
    Format: 503454 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 13
    facet.materialart.
    Unknown
    A Shallow-CISK-Deep-Equilibrium Mechanism for The Interaction Between Large-Scale Convection and Large-Scale Circulations In The Tropics (2005)
    American Meteorological Society
    Details
    Publication Date: 2021-05-19
    Description: In this paper, the circulations driven by deep heating and shallow heating are investigated through analytically solving a set of linear equations and examining circulations simulated by a dry primitive equation model. Special emphasis is placed on the low-level mass (moisture) convergence associated with the forced circulation and the maintenance of the shallow and deep heat sources. It is found that the forced circulation driven by shallow heating is more likely to be trapped horizontally near the heating area but relatively extended in the vertical. As a consequence, diabatic heating can not balance adiabatic cooling due to upward motion. At the levels slightly above the top of the heating, a negative vertical gradient of temperature perturbation appears. For the atmosphere driven by deep heating, however, the temperature perturbation cannot accumulate because the heating signals propagate away very fast, allowing an approximate equilibrium between the convective diabatic heating and adiabatic cooling due to upward motion. The converged moisture associated with circulation driven by shallow heating exceeds the amount needed to maintain the heat source. However, the circulation driven by deep heating does not feed back effectively to the moisture convergence, and thus can not be self-sustaining.
    Description: Center for Ocean-Land-Atmosphere Studies - Calverton
    Description: Published
    Keywords: Atmospheric circulation
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed , Article
    Format: 637515 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 14
    facet.materialart.
    Unknown
    GiardiaDB and TrichDB : integrated genomic resources for the eukaryotic protist pathogens Giardia lamblia and Trichomonas vaginalis (2008)
    Oxford University Press
    Details
    Publication Date: 2022-05-25
    Description: © 2008 The Authors. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License. The definitive version was published in Nucleic Acids Research 37 (2009): D526-D530, doi:10.1093/nar/gkn631.
    Description: GiardiaDB (http://GiardiaDB.org) and TrichDB (http://TrichDB.org) house the genome databases for Giardia lamblia and Trichomonas vaginalis, respectively, and represent the latest additions to the EuPathDB (http://EuPathDB.org) family of functional genomic databases. GiardiaDB and TrichDB employ the same framework as other EuPathDB sites (CryptoDB, PlasmoDB and ToxoDB), supporting fully integrated and searchable databases. Genomic-scale data available via these resources may be queried based on BLAST searches, annotation keywords and gene ID searches, GO terms, sequence motifs and other protein characteristics. Functional queries may also be formulated, based on transcript and protein expression data from a variety of platforms. Phylogenetic relationships may also be interrogated. The ability to combine the results from independent queries, and to store queries and query results for future use facilitates complex, genome-wide mining of functional genomic data.
    Description: Federal funds from the National Institute of Allergy and Infectious Diseases; Department of Health and Human Services, National Institutes of Health (HHSN266200400037C). Funding for open access charge: National Institutes of Health (HHSN266200400037C).
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 15
    facet.materialart.
    Unknown
    The protein that binds to DNA base J in trypanosomatids has features of a thymidine hydroxylase (2007)
    Oxford University Press
    Details
    Publication Date: 2022-05-25
    Description: © 2007 The Author et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. The definitive version was published in Nucleic Acids Research 35 (2007): 2107-2115, doi:10.1093/nar/gkm049.
    Description: Trypanosomatids contain an unusual DNA base J (ß-D-glucosylhydroxymethyluracil), which replaces a fraction of thymine in telomeric and other DNA repeats. To determine the function of base J, we have searched for enzymes that catalyze J biosynthesis. We present evidence that a protein that binds to J in DNA, the J-binding protein 1 (JBP1), may also catalyze the first step in J biosynthesis, the conversion of thymine in DNA into hydroxymethyluracil. We show that JBP1 belongs to the family of Fe2+ and 2-oxoglutarate-dependent dioxygenases and that replacement of conserved residues putatively involved in Fe2+ and 2-oxoglutarate-binding inactivates the ability of JBP1 to contribute to J synthesis without affecting its ability to bind to J-DNA. We propose that JBP1 is a thymidine hydroxylase responsible for the local amplification of J inserted by JBP2, another putative thymidine hydroxylase.
    Description: This work was funded by a grant from the Netherlands Organization for Scientific Research and Chemical Sciences (NWO-CW) to P.B., NIH grant A1063523 to R.S. and NIH grant GM063584 to R.P.H.
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 16
    facet.materialart.
    Unknown
    Exploring the relationship between sequence similarity and accurate phylogenetic trees (2006)
    Oxford University Press
    Details
    Publication Date: 2022-05-25
    Description: © 2006 The Authors. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. The definitive version was published in Molecular Biology and Evolution 23(2006): 2090-2100, doi:10.1093/molbev/msl080.
    Description: We have characterized the relationship between accurate phylogenetic reconstruction and sequence similarity, testing whether high levels of sequence similarity can consistently produce accurate evolutionary trees. We generated protein families with known phylogenies using a modified version of the PAML/EVOLVER program that produces insertions and deletions as well as substitutions. Protein families were evolved over a range of 100–400 point accepted mutations; at these distances 63% of the families shared significant sequence similarity. Protein families were evolved using balanced and unbalanced trees, with ancient or recent radiations. In families sharing statistically significant similarity, about 60% of multiple sequence alignments were 95% identical to true alignments. To compare recovered topologies with true topologies, we used a score that reflects the fraction of clades that were correctly clustered. As expected, the accuracy of the phylogenies was greatest in the least divergent families. About 88% of phylogenies clustered over 80% of clades in families that shared significant sequence similarity, using Bayesian, parsimony, distance, and maximum likelihood methods. However, for protein families with short ancient branches (ancient radiation), only 30% of the most divergent (but statistically significant) families produced accurate phylogenies, and only about 70% of the second most highly conserved families, with median expectation values better than 10–60, produced accurate trees. These values represent upper bounds on expected tree accuracy for sequences with a simple divergence history; proteins from 700 Giardia families, with a similar range of sequence similarities but considerably more gaps, produced much less accurate trees. For our simulated insertions and deletions, correct multiple sequence alignments did not perform much better than those produced by T-COFFEE, and including sequences with expressed sequence tag–like sequencing errors did not significantly decrease phylogenetic accuracy. In general, although less-divergent sequence families produce more accurate trees, the likelihood of estimating an accurate tree is most dependent on whether radiation in the family was ancient or recent. Accuracy can be improved by combining genes from the same organism when creating species trees or by selecting protein families with the best bootstrap values in comprehensive studies.
    Description: This work was supported by National Institutes of Health grant AI1058054 to M. Sogin.
    Keywords: Simulation ; Phylogenetic analysis ; Accuracy ; Sequence similarity
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: 293324 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 17
    facet.materialart.
    Unknown
    Accuracy of a pulse-coherent acoustic Doppler profiler in a wave-dominated flow (2007)
    American Meteorological Society
    Details
    Publication Date: 2022-05-25
    Description: This paper is not subject to U.S. copyright. The definitive version was published in Journal of Atmospheric and Oceanic Technology 21 (2004): 1448–1461, doi:10.1175/1520-0426(2004)021〈1448:AOAPAD〉2.0.CO;2.
    Description: The accuracy of velocities measured by a pulse-coherent acoustic Doppler profiler (PCADP) in the bottom boundary layer of a wave-dominated inner-shelf environment is evaluated. The downward-looking PCADP measured velocities in eight 10-cm cells at 1 Hz. Velocities measured by the PCADP are compared to those measured by an acoustic Doppler velocimeter for wave orbital velocities up to 95 cm s−1 and currents up to 40 cm s−1. An algorithm for correcting ambiguity errors using the resolution velocities was developed. Instrument bias, measured as the average error in burst mean speed, is −0.4 cm s−1 (standard deviation = 0.8). The accuracy (root-mean-square error) of instantaneous velocities has a mean of 8.6 cm s−1 (standard deviation = 6.5) for eastward velocities (the predominant direction of waves), 6.5 cm s−1 (standard deviation = 4.4) for northward velocities, and 2.4 cm s−1 (standard deviation = 1.6) for vertical velocities. Both burst mean and root-mean-square errors are greater for bursts with ub ≥ 50 cm s−1. Profiles of burst mean speeds from the bottom five cells were fit to logarithmic curves: 92% of bursts with mean speed ≥ 5 cm s−1 have a correlation coefficient R2 〉 0.96. In cells close to the transducer, instantaneous velocities are noisy, burst mean velocities are biased low, and bottom orbital velocities are biased high. With adequate blanking distances for both the profile and resolution velocities, the PCADP provides sufficient accuracy to measure velocities in the bottom boundary layer under moderately energetic inner-shelf conditions.
    Description: This work was funded by the U.S. Geological Survey as part of the Southwest Washington Coastal Erosion Study
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 18
    facet.materialart.
    Unknown
    Upgrades to StellaBase facilitate medical and genetic studies on the starlet sea anemone, Nematostella vectensis (2007)
    Oxford University Press
    Details
    Publication Date: 2022-05-25
    Description: © 2007 The Author(s) This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. The definitive version was published in Nucleic Acids Research 36 (2008): D607-D611, doi:10.1093/nar/gkm941.
    Description: The starlet sea anemone, Nematostella vectensis, is a basal metazoan organism that has recently emerged as an important model system in developmental biology and evolutionary genomics. StellaBase, the Nematostella Genomics Database (http://stellabase.org), was developed in 2005 as a resource to support the Nematostella research community. Recently, it has become apparent that Nematostella may be a particularly useful system for studying (i) microevolutionary variation in natural populations, and (ii) the functional evolution of human disease genes. We have developed two new databases that will foster such studies: StellaBase Disease (http://stellabase.org/disease) is a relational database that houses 155 904 invertebrate homologous isoforms of human disease genes from four leading genomic model systems (fly, worm, yeast and Nematostella), including 14 874 predicted genes from the sea anemone itself. StellaBase SNP (http://stellabase.org/SNP) is a relational database that describes the location and underlying type of mutation for 20 063 single nucleotide polymorphisms.
    Description: This work was supported by NSF grant FP-91656101-0 to J.C.S. and J.R.F. and EPA Grant F5E11155 to A.R.M. and J.R.F. and by a Postdoctoral Scholar Program at the Woods Hole Oceanographic Institution, with funding provided by The Beacon Institute for Rivers and Estuaries, and the J. Seward Johnson Fund to A.M.R.
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 19
    facet.materialart.
    Unknown
    Measurements of acoustic scattering from zooplankton and oceanic microstructure using a broadband echosounder (2009)
    Oxford University Press
    Details
    Publication Date: 2022-05-25
    Description: © 2009 The Authors. This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License. The definitive version was published in ICES Journal of Marine Science: Journal du Conseil 67 (2010): 379-394, doi:10.1093/icesjms/fsp242.
    Description: In principle, measurements of high-frequency acoustic scattering from oceanic microstructure and zooplankton across a broad range of frequencies can reduce the ambiguities typically associated with the interpretation of acoustic scattering at a single frequency or a limited number of discrete narrowband frequencies. With this motivation, a high-frequency broadband scattering system has been developed for investigating zooplankton and microstructure, involving custom modifications of a commercially available system, with almost complete acoustic coverage spanning the frequency range 150–600 kHz. This frequency range spans the Rayleigh-to-geometric scattering transition for some zooplankton, as well as the diffusive roll-off in the spectrum for scattering from turbulent temperature microstructure. The system has been used to measure scattering from zooplankton and microstructure in regions of non-linear internal waves. The broadband capabilities of the system provide a continuous frequency response of the scattering over a wide frequency band, and improved range resolution and signal-to-noise ratios through pulse-compression signal-processing techniques. System specifications and calibration procedures are outlined and the system performance is assessed. The results point to the utility of high-frequency broadband scattering techniques in the detection, classification, and under certain circumstances, quantification of zooplankton and microstructure.
    Description: The work was supported by the US Office of Naval Research (Grant # N000140210359).
    Keywords: Broadband acoustic scattering ; Internal waves ; Oceanic microstructure ; Zooplankton
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 20
    facet.materialart.
    Unknown
    Distribution and phylogeny of Penelope-like elements in eukaryotes (2009)
    Oxford University Press
    Details
    Publication Date: 2022-05-25
    Description: Author Posting. © Society of Systematic Biologists, 2006. This article is posted here by permission of Oxford University Press for personal use, not for redistribution. The definitive version was published in Systematic Biology 55 (2006): 875-885, doi:10.1080/10635150601077683.
    Description: Penelope-like elements (PLEs) are a relatively little studied class of eukaryotic retroelements, distinguished by the presence of the GIY-YIG endonuclease domain, the ability of some representatives to retain introns, and the similarity of PLE-encoded reverse transcriptases to telomerases. Although these retrotransposons are abundant in many animal genomes, the reverse transcriptase moiety can also be found in several protists, fungi, and plants, indicating its ancient origin. A comprehensive phylogenetic analysis of PLEs was conducted, based on extended sequence alignments and a considerably expanded data set. PLEs exhibit the pattern of evolution similar to that of non-LTR retrotransposons, which form deep-branching clades dating back to the Precambrian era. However, PLEs seem to have experienced a much higher degree of lineage losses than non-LTR retrotransposons. It is suggested that PLEs and non-LTR retrotransposons are included into a larger eTPRT (eukaryotic target-primed) group of retroelements, characterized by 5' truncation, variable target-site duplication, and the potential of the 3' end to participate in formation of non-autonomous derivatives.
    Description: This work was supported by the U.S. National Science Foundation (MCB 0614142).
    Keywords: Penelope-like elements ; Retrotransposons ; Reverse transcriptase ; GIY-YIG endonuclease
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 21
    facet.materialart.
    Unknown
    uBioRSS : tracking taxonomic literature using RSS (2007)
    Oxford University Press
    Details
    Publication Date: 2022-05-25
    Description: © 2007 The Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. The definitive version was published in Bioinformatics 23 (2007): 1434-1436, doi:10.1093/bioinformatics/btm109.
    Description: Web content syndication through standard formats such as RSS and ATOM has become an increasingly popular mechanism for publishers, news sources, and blogs to disseminate regularly updated content. These standardized syndication formats deliver content directly to the subscriber, allowing them to locally aggregate content from a variety of sources instead of having to find the information on multiple websites. The uBioRSS application is a "taxonomically intelligent" service customized for the biological sciences. It aggregates syndicated content from academic publishers and science news feeds, then uses a taxonomic name entity recognition algorithm to identify and index taxonomic names within those data streams. The resulting name index is cross-referenced to current global taxonomic datasets to provide context for browsing the publications by taxonomic group. This process, called taxonomic indexing, draws upon services developed specifically for biological sciences, collectively referred to as "taxonomic intelligence." Such value-added enhancements can provide biologists with accelerated and improved access to current biological content.
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 22
    facet.materialart.
    Unknown
    Molecular dissection of Penelope transposable element regulatory machinery (2008)
    Oxford University Press
    Details
    Publication Date: 2022-05-26
    Description: © 2008 The Authors. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. The definitive version was published in Nucleic Acids Research 36 (2008): 2522-2529, doi:10.1093/nar/gkm1166
    Description: Penelope-like elements (PLEs) represent a new class of retroelements identified in more than 80 species belonging to at least 10 animal phyla. Penelope isolated from Drosophila virilis is the only known transpositionally active representative of this class. Although the size and structure of the Penelope major transcript has been previously described in both D. virilis and D. melanogaster transgenic strains, the architecture of the Penelope regulatory region remains unknown. In order to determine the localization of presumptive Penelope promoter and enhancer-like elements, segments of the putative Penelope regulatory region were linked to a CAT reporter gene and introduced into D. melanogaster by P-element-mediated transformation. The results obtained using ELISA to measure CAT expression levels and RNA studies, including RT–PCR, suggest that the active Penelope transposon contains an internal promoter similar to the TATA-less promoters of LINEs. The results also suggest that some of the Penelope regulatory sequences control the preferential expression in the ovaries of the adult flies by enhancing expression in the ovary and reducing expression in the carcass. The possible significance of the intron within Penelope for the function and evolution of PLEs, and the effect of Penelope insertions on adjacent genes, are discussed.
    Description: This work was supported by grants from Russian Academy of Sciences (Cell and Molecular Biology to M.E.), and Welcome Trust Grant (075698) to M.E and D.J.F.
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 23
    facet.materialart.
    Unknown
    Why compare marine ecosystems? (2009)
    Oxford University Press
    Details
    Publication Date: 2022-05-26
    Description: This paper is not subject to U.S. copyright. The definitive version was published in ICES Journal of Marine Science: Journal du Conseil 67 (2010): 1-9, doi:10.1093/icesjms/fsp221.
    Description: Effective marine ecosystem-based management (EBM) requires understanding the key processes and relationships controlling the aspects of biodiversity, productivity, and resilience to perturbations. Unfortunately, the scales, complexity, and non-linear dynamics that characterize marine ecosystems often confound managing for these properties. Nevertheless, scientifically derived decision-support tools (DSTs) are needed to account for impacts resulting from a variety of simultaneous human activities. Three possible methodologies for revealing mechanisms necessary to develop DSTs for EBM are: (i) controlled experimentation, (ii) iterative programmes of observation and modelling ("learning by doing"), and (iii) comparative ecosystem analysis. We have seen that controlled experiments are limited in capturing the complexity necessary to develop models of marine ecosystem dynamics with sufficient realism at appropriate scales. Iterative programmes of observation, model building, and assessment are useful for specific ecosystem issues but rarely lead to generally transferable products. Comparative ecosystem analyses may be the most effective, building on the first two by inferring ecosystem processes based on comparisons and contrasts of ecosystem response to human-induced factors. We propose a hierarchical system of ecosystem comparisons to include within-ecosystem comparisons (utilizing temporal and spatial changes in relation to human activities), within-ecosystem-type comparisons (e.g. coral reefs, temperate continental shelves, upwelling areas), and cross-ecosystem-type comparisons (e.g. coral reefs vs. boreal, terrestrial vs. marine ecosystems). Such a hierarchical comparative approach should lead to better understanding of the processes controlling biodiversity, productivity, and the resilience of marine ecosystems. In turn, better understanding of these processes will lead to the development of increasingly general laws, hypotheses, functional forms, governing equations, and broad interpretations of ecosystem responses to human activities, ultimately improving DSTs in support of EBM.
    Keywords: Comparative marine ecosystem analysis ; Decision-support tools ; EAM ; EBM ; Ecological modelling ; Ecosystem approaches to management ; Ecosystem-based management
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 24
    facet.materialart.
    Unknown
    Escherichia coli K-12 : a cooperatively developed annotation snapshot—2005 (2007)
    Oxford University Press
    Details
    Publication Date: 2022-05-26
    Description: © The Author 2006. This article is posted here by permission of Oxford University Press. The definitive version was published in Nucleic Acids Research 34 (2006): 1-9, doi:10.1093/nar/gkj405.
    Description: The goal of this group project has been to coordinate and bring up-to-date information on all genes of Escherichia coli K-12. Annotation of the genome of an organism entails identification of genes, the boundaries of genes in terms of precise start and end sites, and description of the gene products. Known and predicted functions were assigned to each gene product on the basis of experimental evidence or sequence analysis. Since both kinds of evidence are constantly expanding, no annotation is complete at any moment in time. This is a snapshot analysis based on the most recent genome sequences of two E.coli K-12 bacteria. An accurate and up-to-date description of E.coli K-12 genes is of particular importance to the scientific community because experimentally determined properties of its gene products provide fundamental information for annotation of innumerable genes of other organisms. Availability of the complete genome sequence of two K-12 strains allows comparison of their genotypes and mutant status of alleles.
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/vnd.ms-excel
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 25
    facet.materialart.
    Unknown
    Geophysics: Singing icebergs (2005)
    American Association for the Advancement of Science (AAAS)
    In:  EPIC3Science, American Association for the Advancement of Science (AAAS), 310(5752), pp. 1299-1299, ISSN: 0036-8075
    Details
    Publication Date: 2023-06-13
    Description: 〈jats:p〉Sustained harmonic tremor signals were recorded by the seismographs of the German Neumayer Base seismological network in western Dronning Maud Land, Antarctica. These tremor episodes, lasting up to 16 hours, were recorded up to 820 kilometers from the source. Their spectra show narrow peaks with fundamental frequencies ranging from 0.5 to 6 hertz, more than 30 integer harmonic overtones, and frequency gliding, resembling volcanic tremor. Frequency‐wave number analysis suggested a moving source, which was recognized as iceberg B-09A traveling along the coast of eastern Antarctica. The most probable tremor sources are fluid-flow‐induced vibrations inside the iceberg's tunnel/crevasse systems.〈/jats:p〉
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 26
    facet.materialart.
    Unknown
    Avian hybrids: incidence and geographic distribution of hybridisation in birds (2007)
    Oxford University Press
    In:  Handbook of Avian Hybrids of the World vol. 76, 1, pp. 59-61
    Details
    Publication Date: 2024-01-12
    Keywords: book review ; geographic distribution ; hybridisation ; birds
    Repository Name: National Museum of Natural History, Netherlands
    Type: info:eu-repo/semantics/review
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 27
    Electronic Resource
    Electronic Resource
    Determination of diffusion in polycrystalline platinum thin films (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4902-4907 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Grain boundary diffusion of titanium through platinum thin films has been carried out in the temperature range from 200 to 600 °C. Five different platinum/titanium bilayer thicknesses, from 35 to 800 Å Pt, were annealed in 5% O2/95% N2. The accumulation of titanium at the platinum surface layer was measured by x-ray photoelectron spectroscopy (XPS) to determine the grain boundary diffusion coefficient (Db). Diffusivity values were calculated based on two different analysis methods assuming type C kinetics. For Pt layers thicker than 200 Å, the activation energy (Qb) for titanium diffusion was found to be 118±15 kJ/mol (1.22±0.16 eV). For Pt layers thinner than 200 Å, there was a thickness dependence on the diffusion kinetics, resulting in activation energies as low as 20±4 kJ/mol (0.21±0.04 eV). XPS results gave no evidence for any Pt-Ti alloy formation in these layers. The suppression of alloy formation may be attributed to the presence of oxygen at the Pt/Ti interface during layer deposition. The quantitative analysis of titanium interdiffusion in platinum provides valuable information regarding Pt/Ti surface concentrations in thin-film chemical sensors, and for understanding changes in operational characteristics of platinum electrodes. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371458
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Tensile testing of AlCu thin films on polyimide foils (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4922-4929 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Mechanical properties of sputtered AlCu(0.5 wt %) thin films, 0.2–2.0 μm thick, were determined by tensile testing. For comparison, tensile tests were also performed on bulk samples of the same composition. The films were deposited on thin polyimide foils. They were characterized with respect to the surface, microstructure, residual stress, and concentration of copper and oxygen. Stress-strain curves of the films were obtained by separating the force working on the polyimide foil from that working on the metal-polyimide compound. Young's modulus of the films almost corresponded to the bulk value. Films with a thickness 〉1.5 μm broke by formation of macrocracks while thinner films showed formation of microcracks. The Hall–Petch model, additional strengthening by small grain size, and the role of grain boundary sliding for crack formation are discussed. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371461
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Effect of pre-amorphization of polycrystalline silicon on agglomeration of TiSi2 in subquarter micron Si lines (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4943-4948 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We investigated the effect of C49-to-C54 conversion behavior on the agglomeration of Ti-silicide fabricated on subquarter micron polycrystalline Si lines by comparing pre-amorphized samples with conventional ones. Pre-amorphization of polycrystalline Si enhances the C49-to-C54 transformation on subquarter micron linewidths, however, it results in the early development of macroscopic grooves during the second rapid thermal annealing. From these results, we suggest the existence of an extra thermal budget during the second rapid thermal annealing of the pre-amorphized samples, which deteriorates the thermal stability of the C54-TiSi2 featured line. It is also shown that C49-to-C54 transformation on a 0.2 μm linewidth in the conventional samples has two kinds of competing factors when postannealing is added. One is the tendency of C54 transformation and the other is agglomeration of C49-TiSi2 grains. During high temperature annealing (〉850 °C), C49-TiSi2 has been agglomerated by a thinning mechanism instead of transformation into the C54 phase. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371523
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Space charge effects in carrier escape from single quantum well structures (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 5109-5115 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Recently published data on the variation with applied bias and temperature of steady-state photoluminescence and photoconductivity from a series of GaAs/AlGaAs single quantum well p-i-n structures are subjected to detailed theoretical analysis, using phenomenological variables introduced in connection with these results. The data are interpreted as revealing the presence in the well of a space charge, which causes band bending and hence indirectly modifies carrier escape lifetimes. It is shown that the thermionic escape of holes can affect the electron tunneling escape lifetime so that the latter displays a thermal activation energy which is quantitatively similar to the hole well depth. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371487
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Transient electroluminescence of polymer light emitting diodes using electrical pulses (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 5116-5130 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Detailed experimental and theoretical analysis of the pulsed excitation of polymer light emitting diodes is presented. We find a set of universal transient features for a variety of device configurations (different polymers/cathodes) which can be reproduced using our phenomenological numerical model. We find that the temporal evolution of the electroluminescence in response to a step voltage pulse is characterized by: (i) a delay followed by; (ii) a fast initial rise at turn-on followed by; (iii) a slow rise (slower by at least one order of magnitude). The large mobility mismatch between holes and electrons in conjugated polymers allows us to separately time resolve the motion of holes and electrons. We suggest a method for extracting mobility values that takes into account the possible field-induced broadening of carrier fronts, and which is found to be compatible with mobilities determined from constant wave measurements. By using appropriate device configurations it is possible to determine the mobilities of both holes and electrons from a single device. Mobilities for holes and electrons are extracted for a poly(p-phenylenevinylene) copolymer and poly(di-octyl fluorene). © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371488
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Structure and magnetization of arrays of electrodeposited Co wires in anodic alumina (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 5141-5145 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have produced arrays of Co nanowires in anodic porous alumina filters by means of electrodeposition. The structure and magnetization behavior of the wires was investigated with nuclear magnetic resonance (NMR) and magnetization measurements. NMR shows that the wires consist of a mixture of fcc and hcp texture with the (0001) texture of the hcp fraction oriented preferentially perpendicular to the wires. The magnetization direction is determined by a competition of demagnetizing fields and dipole–dipole fields and can be tuned parallel or perpendicular to the wires by changing the length of the wires. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371490
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Effect of Fe doping in La1−xSrxMnO3 (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 5164-5168 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The effects of Fe doping on the magnetic, transport, and magnetoresistance properties are studied for La0.7Sr0.3Mn1−yFeyO3 (y=0–0.18) and La1−xSrxMn0.88Fe0.12O3 (x=0.1–0.50). For increasing y, a peak in the thermal dependence of the resistivity appears and develops at the temperature TPl lower than TC, while the another peak near TC becomes smaller and then disappears. At 78 K the La1−xSrxMn0.88Fe0.12O3 oxides are insulators for x〈0.2 and x〉0.5 and only the lower-temperature metal–insulator transition peak appears for 0.25〈x〈0.45. With increase of x from 0.25, TPl increases, becomes maximum at x=0.4 and then decreases. The temperature dependence of resistivity for the doped samples is quite different from that of the undoped La1−xSrxMnO3 series. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371494
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Abnormal junction leakage characteristics in titanium-capped cobalt disilicide (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 5293-5295 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Abnormal junction leakage characteristics in titanium-capped cobalt disilicide were investigated. The cobalt silicide n+-p junctions, fabricated with different capping layers, were characterized by current–voltage measurements and transmission electron microscopy. The reverse junction leakage currents of Ti-capped 13.5-nm-thick cobalt disilicide (CT) are higher than those of TiN-capped samples. The activation energy of CT at temperatures below 80 °C is 0.41 eV, and its dominant leakage mechanism is consistent with phonon-assisted tunneling. Transmission electron microscopy analysis indicates the existence of island phases and precipitates located at the silicide/Si interface, which are titanium disilicide and CoxTi1−xSi2 phases, as evidenced by energy dispersive spectroscopy. As a result, for the case of CT, the reasons for higher junction leakage currents and their field dependence appear to be the result of the diffusion of Ti atoms into CoSi2 grain boundaries and the resulting formation of TiSi2 and CoxTi1−xSi2 phases, which gives rise to a rougher silicide interface and a close spacing between silicide and the junction. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371513
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    A noninvasive rf probe for the study of ionization and dissociation processes in technological plasmas (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4100-4106 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A swept frequency absorbance plasma diagnostic technique for measurement of self-resonance frequency, intrinsic plasma-tool distributed capacitance, radiative energy loss, and effective plasma capacitance is described. The ex situ probe measures the plasma properties independently of all contributions from the plasma-tool and transmission line connection to the rf supply. The technique employs a swept frequency source and a balanced equal ratio arm bridge to measure the frequency response of the plasma tool after the plasma has been extinguished under plasma conjugate matching conditions. The resonant frequency of the combination of capacitances due to plasma-tool geometry (intrinsic capacitance, Ci) and the matching network (Cm) exhibits a shift from the excitation frequency (13.56 MHz) that is dependent on the effective plasma capacitance. Resonance frequency shift data are given for He, Ne, Ar, O2, N2, and N2O as a function of both pressure (0.02–0.8 mbar) and incident power (50 and 100 W). This technique allows the differentiation between dissociation and ionization processes within the plasma through a simple noninvasive rf measurement. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371334
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Charge distribution function of plasma dust particles with secondary electron emission (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4118-4123 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The charge distribution function (CDF) of dust particles in low temperature plasmas is obtained as a function of both negative and positive discrete charges Z=(minus-plus)1,(minus-plus)2;,..., and various plasma parameters. Positively charged grains can be formed when secondary electron emission, that is, ionization of the grains by electron impact, is sufficiently important to change their charge. An expression for the CDF is derived from steady-state master equations for the densities of monodispersed, negatively or positively charged dust particles, with Z=(minus-plus)1,(minus-plus)2,... discrete elementary charges and radius R, taking into account single and double elementary charge changes in collisions of the particle with plasma electrons or ions. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371336
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Role of Ar2+ and Ar2+ ions in a direct current argon glow discharge: A numerical description (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4124-4133 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A two-dimensional model has been developed for calculating the behavior of Ar2+ and Ar2+ ions in a direct current argon glow discharge, by the use of balance equations describing the various production and loss processes for these species, as well as their transport by diffusion and migration. These balance equations are coupled to the equations for the Ar+ ions and electrons and solved simultaneously with Poisson's equation, to obtain a self-consistent description of the charged particles behavior and the electrical characteristics in the glow discharge. Moreover, this model is combined with the other models that we have developed previously for the Ar atoms in various excited levels and the Cu atomic and ionic species, to obtain an overall description of the direct current argon glow discharge. The model is applied to typical conditions used for glow discharge mass spectrometry (pressure of 50–100 Pa, voltage of 600–1400 V, and current of 0.4–15 mA). Typical calculation results include the densities and fluxes of these ionic species, as well as the relative contributions of their production and loss processes. The Ar2+ ions are almost exclusively formed by two-electron ionization from Ar0 atoms, and they become primarily lost by diffusion and subsequent recombination at the cell walls. The Ar2+ ions are mainly created by Hornbeck–Molnar and metastable-metastable associative ionization, whereas atom to molecule conversion seems to play only a minor role at the discharge conditions under study. Loss of these Ar2+ ions is caused primarily by diffusion and recombination at the cell walls, but dissociative recombination in the plasma plays also a significant role. We found that the ratios of Ar2+/Ar+ and Ar2+/Ar+ ion densities and fluxes were in the order of 1%–10%, which is in good agreement with experimental observations. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371337
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Sensitivity of near-edge x-ray absorption fine structure spectroscopy to ion beam damage in diamond films (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4192-4198 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In the present work, we study the sensitivity of the near-edge x-ray absorption fine structure (NEXAFS) spectroscopy to ion induced defects in polycrystalline diamond films. The ion bombardment of hydrogenated films is performed using 30 keV Xe+ ions at room temperature for doses ranging from 2×1013 ions/cm2, producing local point defects, to 2×1015 ions/cm2, which results in almost complete amorphization of the diamond surface. Auger electron spectroscopy measurements are not sensitive to the modifications induced by the lowest implantation dose. Whereas partial electron yield (PEY) NEXAFS measurements, applied in surface and bulk-sensitive modes, using 35, 15, and 8 eV secondary electrons, respectively, reveals the formation of a defective structure and gradual deterioration of diamond in the near-surface region. From PEY NEXAFS spectra measured using 15 eV secondary electrons, the position of C(1s) binding energy is measured. The x-ray photoelectron spectra of the samples were measured using an incident photon energy of 450 eV. It is found that the C(1s) binding energy in the implanted samples has a positive shift of 0.6–1 eV, which is indicative of transformation of diamond to disordered carbon. The high sensitivity of NEXAFS spectroscopy to point defects induced by the low dose ion implantation was reflected by a sharp reduction in the intensity of the diamond core exciton peak and by the appearance of a new spectral feature in the pre-edge region, below the C(1s)−π* transition. Analysis of the NEXAFS spectra of ion implanted films is performed on the basis of the electronic structure of diamond. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371346
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Nematic polar anchoring strength measured by electric field techniques (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4199-4213 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We analyze the high-electric-field technique designed by Yokoyama and van Sprang [J. Appl. Phys. 57, 4520 (1985)] to determine the polar anchoring coefficient W of a nematic liquid crystal-solid substrate. The technique implies simultaneous measurement of the optical phase retardation and capacitance as functions of the applied voltage well above the threshold of the Frederiks transition. We develop a generalized model that allows for the determination of W for tilted director orientation. Furthermore, the model results in a new high-field technique, (referred to as the RV technique), based on the measurement of retardation versus applied voltage. W is determined from a simple linear fit over a well-specified voltage window. No capacitance measurements are needed to determine W when the dielectric constants of the liquid crystal are known. We analyze the validity of the Yokoyama–van Sprang (YvS) and RV techniques and show that experimental data in real cells often do not follow the theoretical curves. The reason is that the director distribution is inhomogeneous in the plane of the bounding plates, while the theory assumes that the director is not distorted in this plane. This discrepancy can greatly modify the fitted value of 1/W, and even change its sign, thus making the determination of W meaningless. We suggest a protocol that allows one to check if the cell can be used to measure W by the YvS or RV techniques. The protocol establishes new criteria that were absent in the original YvS procedure. The results are compared with other data on W, obtained by a threshold-field technique for the same nematic-substrate pair. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371347
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Gettering of Cu by microcavities in bonded/ion-cut silicon-on-insulator and separation by implantation of oxygen (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4214-4219 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Microcavities formed by H+ and He+ implantation and subsequent annealing are effective gettering sites for transition metal impurities in silicon. However, gettering in silicon-on-insulator (SOI) materials is quite different from that in silicon. In this work, we investigate the gettering of Cu to these microcavities in silicon, separation by implantation of oxygen (SIMOX) and bonded/ion-cut SOI wafers. Our data indicate that He+ implantation in the high dose regime (0.2–1×1017 cm−2) creates a wide band of microcavities near the projected range without causing blistering on the sample surface. On the other hand, the implantation dose of H+ needed for stable microcavity formation is relatively narrow (3–4×1016 cm−2), and this value is related to the projected range. The different behavior of H and He in silicon is discussed and He implantation is more desirable with regard to impurity gettering. Cu is implanted into the surface region of the Si and SOI samples, followed by annealing at 700 and 1000 °C. Our results indicate that the microcavities can effectively getter a high dose of Cu (2.5×1015 cm−2) at 700 °C in bulk Si wafer, but higher temperature annealing is needed for the effective gettering in SIMOX. Gettering of Cu by the intrinsic defects at or beneath the buried oxide interface of the SIMOX is observed at 700 °C, but no trapped impurities are observed after 1000 °C annealing in the samples in the presence of microcavities. Almost all of the 1×1014 cm−2 Cu implanted into the Si overlayer of the bonded/ion-cut SOI diffuse through the thermally grown oxide layer and are captured by the cavities in the substrate after annealing at 1000 °C. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371348
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Viscoelastic crack healing and adhesion (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4232-4241 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Closing cracks in viscoelastic materials are analyzed using a cohesive zone model. The analysis is relevant to the bonding of surfaces of viscoelastic materials, and in particular to the Johnson–Kendall–Roberts (JKR) experiment. A crack bonding theory due to Schapery is extended to include the case of the standard linear solid material, and some consequences of this material's finite long time compliance are illustrated. The stress field behind a steadily closing crack in a standard linear solid is also investigated in detail. Finally, a method for applying Schapery's crack bonding theory to the analysis of a JKR-type experiment involving viscoelastic cylinders is given explicitly. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371351
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Investigation of nanostructures in ordinary Portland cement through positron annihilation lifetime spectroscopy (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4225-4231 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Early hydration (up to four weeks) of five ordinary Portland cement pastes with different water-to-cement ratios (0.3, 0.4, 0.5, 0.6, and 1.0 wt) was investigated through positron annihilation lifetime spectroscopy. Measurements were performed at four different hydration times (1 day and 1, 2, and 4 weeks) and compared with results obtained from thermogravimetric analyses. Deconvolution of positron spectra allowed us to separate orthopositronium annihilations in the evacuated gel pores from those in the pores containing water, and therefore, to monitor the pores' evolution with aging time. It is found that the concentration of gel pores increases with aging time, as well as by increasing the content of water in the paste; on the other hand, the typical sizes of the pores do not show significant variations, either with aging time or with the water-to-cement ratio.© 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371350
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    High-speed spin-polarized intersubband lasers (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4734-4739 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Spin-polarized intersubband lasers based on optically pumped type-II antimonide quantum wells in a magnetic field are proposed. Complete discretization of the electron energy spectrum is predicted to extend the electron lifetime considerably. Continuous-wave room-temperature operation is projected for both interband and intersubband pumping configurations lasing at λ=16–24 μm. Furthermore, the parasitic capacitances associated with electrical injection are eliminated, and the large differential gain and fast intrinsic time scale should give modulation bandwidths in excess of 100 GHz. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371437
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Ion behavior and gas mixing in electron cyclotron resonance plasmas as sources of highly charged ions (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4772-4779 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: This article deals with ion behavior in small open-ended magnetic devices, the electron cyclotron resonance ion sources (ECRIS) that were developed for multicharged ion production. The ECRIS are basically ECR-heated plasma confinement machines with hot electrons and cold ions. The main parameters of the ion population in ECRIS plasmas are successively analyzed: temperature, collisions, losses, confinement times, followed by the gas mixing effect, a specific technique to improve the performance as an ion source. A series of experiments is described for the systematic analysis of this effect. It is experimentally shown that high charge state optimization by gas mixing results from an ion confinement time improvement due to ion cooling, and relies on a compromise between three criteria, ion losses, mass effect, and ionization rates. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371442
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Effect of a magnetic field on the plasma plume from Hall thrusters (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4786-4791 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An axial profile of the quasineutral plasma jet exhaust from a Hall thruster is studied. The plasma jet expansion is modeled using the sourceless steady-state hydrodynamic equations. It is considered that the plasma jet has a conical shape with a half angle of about 40°. The magnetic field surrounding the Hall thruster exit is included in the calculation. It is found that a magnetic field may significantly affect the axial profile of the plasma potential. For instance, in the case of zero magnetic field, the plasma potential is about −10 V at 1 m from the thruster exit, while in the case of a 0.1 T magnetic field, the plasma has a potential of about +25 V. Results predicted by the model are found to be in good agreement with experimental data for three different Hall thruster designs. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371444
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Indium-modified growth kinetics of cubic and hexagonal GaN in molecular beam epitaxy (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4322-4325 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The kinetics changes in the growth of GaN induced by the presence of In segregated on the surface have been investigated in situ by using reflection high energy electron diffraction intensity oscillations. Two types of surfaces have been studied, namely, Ga-polar (0001) wurtzite, and (001) zinc blende. It has been found that In influenced both Ga and N surface kinetics, leading to a change in the growth rate associated with a change in the amount of Ga and N effectively available for the GaN growth. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371364
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Investigation of nitric oxide and Ar annealed SiO2/SiC interfaces by x-ray photoelectron spectroscopy (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4316-4321 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Silicon dioxide (SiO2)/silicon carbide (SiC) structures annealed in nitric oxide (NO) and argon gas ambiences were investigated using x-ray photoelectron spectroscopy (XPS). The XPS depth profile analysis shows a nitrogen pileup of 1.6 at. % close to the NO annealed SiO2/SiC interface. The results of Si 2p, C 1s, O 1s, and N 1s core-level spectra are presented in detail to demonstrate significant differences between NO and Ar annealed samples. A SiO2/SiC interface with complex intermediate oxide/carbon states is found in the case of the Ar annealed sample, while the NO annealed SiO2/SiC interface is free of these compounds. The Si 2p spectrum of the Ar annealed sample is much broader than that of the NO annealed sample and can be fitted with three peaks compared with the two peaks in the NO annealed sample, indicating a more complex interface in the Ar annealed sample. Also the O 1s spectrum of the NO annealed samples is narrow and symmetrical and can be fitted with only one peak whereas that of the Ar annealed sample is broad and asymmetrical and is fitted with two peaks. It is evident that the Ar annealed sample contains some structural defects at the interface, which have been removed from the interface by NO annealing as shown by O 1s spectra. The C 1s spectra at the interface reveal the subtle difference between NO and Ar annealed samples. An additional peak representing the interface oxide/carbon species is observed in the Ar annealed sample. At the interface, the N 1s spectrum is symmetrical and can be fitted with one peak, representing the strong Si(Triple Bond)N bond. However, the N 1s and C 1s XPS spectra acquired in the bulk of the dielectric showed not only the Si(Triple Bond)N bond but also a trace amount of the N–C bond. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371363
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Nondestructive evaluation of channel carrier concentration in modulation-doped InAlAs/InGaAs field-effect transistor structures by room-temperature photoluminescence (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4333-4340 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The sheet carrier concentration (Ns) of channel layers in modulation-doped InAlAs/InGaAs heterostructure field-effect transistor (HFET) structures with n+InGaAs contact layers has been successfully and nondestructively determined using the room-temperature photoluminescence (PL) method. It is found that the spectral energy width between the maximum position of the main PL peak around 0.8 eV and the half-maximum position on the higher energy side has a good positive linear correlation with the Ns of the channel measured by the van der Pauw method. The scattering of the data is less than ±3×1011 cm−2. The determination of Ns is effective even if the HFET structures have not only n+InGaAs contact layers but also layers for InAlAs Schottky level-shift diodes. From a comparison with low-temperature PL spectra, the main PL peak is attributed to the e2h transition in the quantum well of the channel. It is considered that the slope of the peak stretches further to the high energy as the Fermi energy in the channel become higher, i.e., as the Ns becomes larger. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371366
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Photoluminescence and Zeeman effect in chromium-doped 4H and 6H SiC (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4348-4353 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Photoluminescence (PL) and Zeeman effect measurements in near-infrared luminescence bands in Cr-doped 4H and 6H SiC are presented. The PL spectrum consists of two no-phonon lines (NPLs) at 1.1583 and 1.1898 eV in 4H SiC and three NPLs at 1.1556, 1.1797, and 1.1886 eV in 6H SiC. The observed Zeeman splittings and temperature dependence studies reveal the spin triplet of the ground state and the orbital doublet structure of the excited state of the Cr-related center. All the triplets have almost isotropic g values close to 2 with trigonal symmetry and small zero-field splitting values D. In contrast, the effective g values of the excited state of the center are very anisotropic with g(parallel) in the range of 0.22–0.64 and g⊥=0 for different NPLs in both polytypes. Based on the Zeeman results, the PL is attributed to the internal transition 1E(D)→3A2(F) within the d shell of a substitutional, neutral chromium (Cr4+) in the 3d2 electronic configuration. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371368
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Synchrotron characterization of deep depletion epitaxial GaAs detectors (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4341-4347 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report the results of a series of synchrotron characterizations of two epitaxial GaAs detectors of active areas 2.22 mm2 and thicknesses 40 and 400 μm. In spite of an order of magnitude difference in depletion depths, the detectors were found to have comparable performances at ∼−40 °C, with energy resolutions of ∼1 keV full width at half maximum (FWHM) at 7 keV rising to ∼2 keV FWHM at 200 keV and noise floors in the range of 1–1.5 keV. At the lower energies, the energy resolution was dominated by leakage current and electromagnetic pickup. At the highest energies, however, the measured resolutions appear to approach the expected Fano limit; e.g., ∼950 eV at 200 keV. Both detectors were remarkably linear, with average rms nonlinearities of 0.2% over the energy range of 10–60 keV. By raster scanning the active areas with 20×20 μm2 monoenergetic photon beams, it was found that the nonuniformity in the spatial response of both detectors was less than 1% and independent of energy. The material used to fabricate the detector is extremely pure. For example, low temperature photoluminescence measurements indicate that the density of the As antisite defect (EL2) is of the order of 1012 cm−3, which is ∼2–3 orders of magnitude lower than that generally reported. This indirect measurement of material purity is confirmed by Monte Carlo simulations of the detector x-ray response, which show that in order to reproduce the observed energy-loss spectra, electron and hole trapping cross-section/density products must be (very-much-less-than)1 cm−1. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371367
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Optical characterizations of CuInSe2 epitaxial layers grown by molecular beam epitaxy (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4354-4359 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: CuInSe2 (CIS) films with Cu/In ratios of γ=0.82–1.79 have been grown on a GaAs (001) substrate by molecular beam epitaxy. Piezoelectric photoacoustic (PPA) measurements were carried out from liquid helium to room temperature to investigate nonradiative carrier recombination processes in comparison with photoluminescence (PL) measurements which directly detected radiative carrier recombination processes. Three PPA signal peaks which corresponded to band gap energies of the CIS (AB and C bands) and the GaAs substrate, were clearly obtained between liquid helium and room temperatures. A free-exciton emission line was observed up to 200 K in the PL spectra. Two additional peaks on intrinsic defects which are Cu vacancy (VCu) and interstitial In (Ini) were observed in the In-rich CIS samples. The PPA measurements were useful in investigating the defect levels and the band gap energy in the CIS/GaAs thin films. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371369
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Electroabsorption studies on quasi-three-dimensional and quasi-two-dimensional excitons in (Zn,Cd)Se/Zn(S,Se) structures (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4360-4364 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The electro-optical properties of (Zn,Cd)Se/Zn(S,Se) quantum well structures grown on GaAs substrates have been studied with differential electroabsorption spectroscopy at room temperature and compared to model calculations. (Zn,Cd)Se wells of 20, 10, and 4×5 nm are investigated, corresponding to well widths of four, two, and one times the exciton Bohr radius in this material system, respectively. We observe the quantum confined Stark effect for the 4×5 nm sample and find a Stark shift of 18 meV in the heavy-hole exciton peak for an electric field change from 82 to 175 kV/cm. In contrast, the 10 nm sample shows a rather weak and more Franz–Keldysh-like signal. We show that the 20-nm-thick quantum-well sample behaves like bulk material, i.e., the electro-absorption signal is well described by Franz–Keldysh oscillations. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371370
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Interaction between guided optical waves and magnetostatic waves in bismuth-doped yttrium–iron–garnet waveguide under inclined magnetic fields (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4365-4368 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The noncollinear interaction between guided optical waves and magnetostatic waves under inclined bias magnetic field is studied in detail. The diffraction efficiency (DE) and the mode-conversion efficiency (MCE) of guided optical waves with magnetostatic forward volume waves in the bismuth-doped yttrium–iron–garnet (Bi-doped YIG) waveguide are calculated numerically. The calculation results indicate that the DE and the MCE are different in physical conception and the DE is not equal to the MCE in magnitude under inclined bias magnetic field. The DE may be greatly increased by using an appropriately inclined bias magnetic field, which has been experimentally confirmed in a pure YIG waveguide. By using an inclined bias magnetic field and the Bi-doped YIG waveguide, under the phase-matching conditions, the maximum DE can come up to 79.5% or more. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371371
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Raman study of the topology of InAs/GaAs self-assembled quantum dots (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4387-4389 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The topology of self-assembled InAs/GaAs quantum dots was studied by resonant Raman scattering caused by the interface modes localized near the edges of the dots. Evidences were found that on both sides of the InAs layer containing the dots, their topologies show some resemblances. In addition, in the multilayered systems the evidence of the coalescence of the dots (which form vertical columns) in neighbor layers separated by the distance smaller than 25 monolayers was obtained. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371375
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Giant magnetic viscosity in SmCo5−xCux alloys (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 5157-5163 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Hysteresis loops in SmCo5−xCux as-cast and annealed magnets (1〈x≤3) were measured at room temperature using a pulsed-field magnetometer and a static vibrating sample magnetometer. At field sweeps between 2 and 17 (GA/m)/s a giant—in this field range nearly constant—magnetic viscosity Sv was obtained. The viscosity is approximately proportional to the Cu concentration and to the coercive field. A heat treatment at 1273 K for three weeks changes the microstructure and enhances strongly the intensity and the time dependence of the coercivity. The decay of the inverse of the coercive field Hc with time follows a simple ln(t) relation between 10−5 and 10 s. Data analysis allows a density of stacking faults N to be extracted for each sample. Sv (and Hc) increases with N which increases with x. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371493
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Angular dependence of exchange anisotropy in Ni81Fe19/CrMnPtx bilayers (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 5169-5174 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have investigated the unidirectional exchange anisotropy between a ferromagnetic (FM) Ni81Fe19 film and a disordered antiferromagnetic (AF) CrMnPtx (x=3, 6, or 9) film. The angular dependence of the exchange coupling in these FM/AF bilayers has been measured. We show that the complex angular dependence of this exchange coupling can be understood by a simple Stoner–Wohlfarth model involving only a uniaxial anisotropy and a unidirectional exchange coupling. Numerical results are in excellent agreement with the experimental data. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371495
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    1/f noise in n-channel metal-oxide-semiconductor field-effect transistors under different hot-carrier stresses (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 5203-5206 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Degradation mechanisms contributing to increased 1/f noise of n-channel metaloxide-semiconductor field-effect transistors (n-MOSFETs) after different hot-carrier stresses are investigated. It is demonstrated that for any hot-carrier stress, the stress-induced enhancement of 1/f noise is mainly attributed to increased carrier-number fluctuation arising from created oxide traps, while enhanced surface-mobility fluctuation associated with electron trapping at preexisting and generated fast interface states and near-interface oxide traps is also responsible under maximum substrate- and gate-current stresses. Besides thermal-oxide n-MOSFETs, nitrided-oxide devices are also used to further support the above analysis. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371501
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Double-barrier THz source based on electrical excitation of electrons and holes (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 5215-5231 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A detailed dynamical analysis of an all solid-state THz source is given. This is based on the polarization-induced autonomous oscillation in resonant tunneling heterostructure with staggered band-gap alignment. The physical model consists of the following processes: (a) Generation by Zener tunneling of holes trapped in the barrier and electrons drifting in the depletion layer of the drain, whose rate decreases with the polarization between the barrier and quantum well. (b) Stimulated generation of barrier-well polarization. (c) Nonradiative decay of barrier-well polarization through barrier-hole recombination and quantum-well electron discharge. It is shown that a limit cycle oscillation of the barrier-well polarization and trapped-hole charge in the barrier can occur which induce THz oscillations in the resonant tunneling current across the device. The time-averaged results agree with the measured current–voltage characteristic of AlGaSb/InAs/AlGaSb staggered band-gap double-barrier structure. In particular, the measured smaller current offset at forward bias compared to that of reverse bias in the current–voltage hysteresis loop is predicted by our physical model and limit cycle analysis. Thus, we have experimental evidence indicating the correctness of our approach and the promising potential of this device as a novel all solid-state THz source. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371503
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Van der Waals and capacitive forces in atomic force microscopies (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 5245-5248 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In this article we show that in the atomic force microscopy experiments performed on a metallic surface, there is always a long range electrostatic force in addition to the van der Waals forces. This capacitive force is due to the contact potential between the tip and the surface and exists even without external applied potential. We have calculated this capacitive force for a real geometry of the tip–sample system and compared it to the van der Waals force calculated for the same geometry. We conclude that the electrostatic force is always dominant for a tip–surface distance larger than half of the tip radius of curvature. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371506
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Adsorption site determination of light elements on heavy substrates by low-energy ion channeling (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 5256-5262 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Ion channeling in the low-keV energy range is demonstrated by means of the technique of time-of-flight scattering and recoiling spectrometry. The predictions of the Lindhard string model of ion channeling are compared with the experimental findings. Qualitative agreement was obtained between the experimentally measured critical angles and the predictions of the model. The technique of low-energy ion channeling is shown to be capable of quantitatively probing the positions of light elements on heavy substrates with analysis by simple geometrical constructs. Classical ion trajectory simulations using the scattering and recoiling imaging code were used to observe the details of the ion trajectories. Quantitative analysis of the Pt(111)-(1×1)-H surface using 5 keV Ne+ shows that the hydrogen atoms preferentially populate the threefold fcc sites with a height of 0.9±0.1 Å above the first-layer Pt atoms and a corresponding Pt–H bond length of 1.9±0.1 Å. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371508
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Effect of annealing on Ge-doped SiO2 thin films (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 5270-5273 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Thermal annealing effects on optical and structural properties of Ge-doped SiO2 thin films prepared by the chemical vapor deposition and flame hydrolysis deposition methods were investigated. The thin film prepared by the former method showed inhomogeneous Ge distribution, and Ge oxygen-deficient centers were observed. When it was thermally annealed at temperatures higher than 800 °C, the Ge distribution became uniform. The concentration of oxygen deficient centers was found to decrease with the thermal annealing in an O2 atmosphere, while it increased with the thermal annealing at 1000 °C in N2. This suggests that improvement of the film quality can be achieved by thermal annealing. On the other hand, neither inhomogeneity of Ge distribution nor the appearance of oxygen deficient centers was observed in the film prepared by the latter method, and its film quality was scarcely affected by the thermal annealing. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371525
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Numerical and experimental studies on synthesis of ultrafine nanosize powders of AlN by ion beam evaporation (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 5279-5285 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Synthesis of ultrafine nanosize powders by ion beam evaporation (IBE) has been studied numerically and experimentally. Theoretical models have been developed, which involve such physical processes as beam-target interaction, plasma expansion, and the synthesis of powders. The macroscopic properties of the ultrafine powders have been predicted. As an application of our models, the macroscopic properties of AlN powders synthesized by IBE with an AlN target have been predicted. The energy density, pulse width, and spot size of the ion beam are 20 J/cm2, 70 ns, and 1 cm2, respectively. The main results have shown that the particle size distribution is log normal and that 70% of all particles exist between 20 and 40 nm. The average diameter and the specific surface area are ∼30 nm and ∼50 m2/g, respectively. Experimentally, the ultrafine AlN powders have been successfully synthesized by IBE, which has been verified by x-ray diffraction and transmission electron diffraction. Furthermore, particle size distributions have been obtained by transmission electron microscopy. The experimental results are found to be in a reasonable agreement with the numerical studies. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371511
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Response to "Comment on ‘Monte Carlo simulation of the laser-induced plasma plume expansion under vacuum: Comparison with experiments' " [J. Appl. Phys. 86, 4709 (1999)] (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4711-4712 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: This response recalls the bases of the Monte Carlo methods of gas flow simulations. Basic points and explicit parameters used in both the DSMC method and the method of random trajectories are underlined. Some clarifications are made on the confusion made by the author of the comment on this subject. The justification of the validity of the method is recalled, as already made in the original article. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371431
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Broad band p-Ge optical amplifier of terahertz radiation (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3512-3515 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A solid state broad band amplifier of terahertz radiation (1.5–4 THz), based on intersubband transitions of hot holes in p-Ge is demonstrated. The gain is investigated as a function of applied magnetic and electric fields by transmission measurements using a laser system with two p-Ge active crystals, when one operates as an oscillator and one as an amplifier. A peak gain higher than usually reported for p-Ge lasers has been achieved using time separated excitation of the oscillator and amplifier. Distinct differences in gain dependence on applied fields are noted between low- and high-frequency modes of p-Ge laser operation. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371250
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Lasers in dense gases pumped by low-energy electron beams (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3525-3529 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The use of low-energy ((approximate)15 keV) electron beams for pumping laser systems in dense gases with high specific power deposition is described. Thin (300 nm) SiNx ceramic foils used as entrance window in a transverse geometry for the electron beam allows pressure differentials of several atmospheres with low percentage energy loss in transmission. The 1.73 μm XeI (5d[3/2]1–6p[5/2]2) infrared laser was used for a first demonstration of this concept. The laser operated between 130 and 650 mbar. A threshold pumping power of 5.3 W and a maximum output power of 6 mW were observed. The system can be scaled to high pumping power ((approximate)MW/cm3) and short wavelength. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371253
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Growth of particles in cluster-size range in low pressure and low power SiH4 rf discharges (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3543-3549 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Growth processes of particles in a cluster-size range below a few nm in size in low pressure and low power SiH4 rf discharges are studied using the new method, in which the threshold photoemission method is coupled with the microwave interferometry, for measurements of their size and density. The density of particles is above 1010 cm−3 and much exceeds that of positive ions, the result of which shows that most of them are neutral. The particles grow mainly around the plasma/sheath boundary near the powered electrode and their size growth rate is 3.4–4.4 nm/s, being much higher than a film growth rate of 0.064–0.12 nm/s. These features strongly indicate that their growth is due to deposition of polymerized species, originated from short lifetime SiH2 radicals, on them, while coagulation between particles becomes appreciable after a time when their density reaches about 1011 cm−3. Moreover, the pulse modulation of rf discharge is found to be effective in reducing the density of cluster-size particles. The reduction can be explained by a model taking account of diffusion of the polymerized species through the radical production region, where the particles nucleate and grow. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371256
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Molybdenum substitutional doping and its effects on phase transition properties in single crystalline vanadium dioxide thin film (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 5311-5313 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Molybdenum (Mo) doped vanadium dioxide thin films were synthesized using a Mo striped vanadium (V) target during pulsed laser ablation process. The film structure was characterized by high resolution x-ray diffraction, x-ray rocking curve and Rutherford backscattering/channeling measurements. The results show that the full width at half magnitude of the x-ray rocking curve is as narrow as 0.0074°, comparable to that of the (0001) sapphire substrate, 0.0042°, in this study. The ratio of the aligned-to-random backscattered yield reaches 5%, implying that the growth is that of the single crystalline epitaxy. The result of angular scans for both V and Mo atomic channelings reveals that Mo atoms successfully take sites of the V sublattice as a substitutional dopant. It has been noted that the degradation of the phase transition properties of the film upon doping is closely related to the conductivity in the semiconductor phase. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371519
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Simulation of the dynamics of twisted nematic devices including flow (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4091-4095 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have modeled the switching behavior of a twisted nematic cell using the one-dimensional Ericksen–Leslie equations of nematodynamics. We compare the modeling results with experimental data on transmission versus time. Excellent agreement between experiment and model is achieved at all voltages and viewing angles. To achieve this agreement, only two viscosity parameters are required; these are combinations of the Leslie viscosity coefficients, namely, α3−α2 (the rotational viscosity) and α4+α5. A fast and stable adaptive numerical algorithm, based on an effective viscosity parameter, is developed for solving the equations of motion. The viscosity parameters obtained from fitting the flow experiments are in good agreement with those obtained from dynamic light-scattering measurements. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371333
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Transparent stacked organic light emitting devices. II. Device performance and applications to displays (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4076-4084 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Vertical stacking of organic light emitting devices (OLEDs) that emit the three primary colors is shown to be a means for achieving efficient and bright full-color displays. In Paper I, we addressed stacked OLED (SOLED) design and fabrication principles to optimize emission colors, operating voltage, and efficiency. Here, we present results on two different (metal-containing and metal-free cathode) SOLED structures that exhibit performance suitable for many full-color display applications. The operating voltages at 10 mA/cm2 (corresponding to video display brightnesses) are 6.8, 8.5, and 12.1 V for the red (R), green (G), and blue (B) elements of the metal-containing SOLED, respectively. The respective subpixel luminous efficiencies are 0.53, 1.44, and 1.52 cd/A, and the Commission Internationale de L'Éclairage (CIE) chromaticity coordinates are (0.72, 0.28), (0.42, 0.56), and (0.20, 0.22). In the high transparency metal-free SOLED, an insulating layer was inserted between the two upper subpixels to allow for independent grounding of all color emitters in the stack. At operating voltages of 12–14 V, video display brightnesses were achieved with luminous efficiencies of 0.35, 1.36, and 1.05 cd/A for the R, G, and B subpixels, respectively. The respective CIE coordinates for R, G, and B emissions are (0.72, 0.28), (0.26, 0.63), and (0.17, 0.28) in the normal viewing direction, shifting inperceptibly as the viewing angle is increased to as large as 60°. Finally, we discuss addressing schemes of SOLED displays, and compare them with other strategies for achieving full-color, OLED-based displays. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371428
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Fast polarization switching with memory effect in a vertical cavity surface emitting laser subject to modulated optical injection (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4096-4099 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The polarization state of a vertical cavity surface emitting laser (VCSEL) output was driven by means of optical injection from another VCSEL. The bistability inherent to polarization locking allowed us to generate a memory effect. The control parameter was the modulated bias current of the maser laser and effects were shown to exist at frequencies up to 1 GHz. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371429
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    High-frequency modulation of an electron beam produced by a plasma cathode (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4107-4117 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We present a detailed study of the recently discovered modulation at frequencies of hundreds of MHz of an electron beam produced by a plasma cathode. The plasma cathode consists of a ferroelectric disk sample [BaTiO3 or Pb(Zr, Ti)O3] that is placed in a cylindrical metal box having an output window covered by a grid. The plasma is prepared by an incomplete discharge that was ignited by a few kV driving pulse applied across the ferroelectric disk. It was shown that the current modulation appears only when the driving pulse is applied to the front gridded electrode of the ferroelectric sample and the solid rear electrode is grounded. The modulation spectrum is quite narrow (≤3%), with harmonics at frequencies up to a few GHz. The basic frequency of modulation was found to be dependent on the length of the feed cable to the sample. Investigation of the plasma and the beam modulation properties and their dependence on the experimental parameters is presented. The results indicate the formation of a plasma at the vicinity of the front electrode of the ferroelectric sample during the modulation. The results are discussed within the frame of electrons oscillating in the potential well created by the positively charged plasma having feedback coupling with the input cable. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371335
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Room-temperature vacancy migration in crystalline Si from an ion-implanted surface layer (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4861-4864 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Migration of vacancies in crystalline, n-type silicon at room temperature from Ge+-implanted (150 keV, 5×109–1×1011 cm−2) surface layers was studied by tracing the presence of P–V pairs (E centers) in the underlying layer using deep level transient spectroscopy (DLTS). Under the conditions we have examined, the vacancies migrate to a maximum depth of about 1 μm and at least one vacancy per implanted Ge ion migrates into the silicon crystal. The annealing of the E centers is accompanied, in an almost one-to-one fashion, by the appearance of a new DLTS line corresponding to a level at EC−Et(approximate)0.15 eV that has donor character. It is argued that the center associated with this line is most probably the P2–V complex; it anneals at about 550 K. A lower limit of the RT-diffusion coefficient of the doubly charged, negative vacancy is estimated to be 4×10−11 cm2/s. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371453
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Site selectively excited luminescence and energy transfer of X1-Y2SiO5:Eu at nanometric scale (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3751-3757 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Two different types of structure called X1 and X2 are existing in Y2SiO5 at normal conditions. In X1 type, Y3+ ions occupy two sites where they are surrounded respectively by nine and seven oxygen ions, while in X2 structure, only six and seven oxygen ions are involved. Nanometric scale X1-Y2SiO5 crystals were prepared by sol-gel method with particle size around 50 nm. Site selective excitation at low temperature has shown four different luminescent centers. Two of them belong to Eu3+ embedded in X1-Y2SiO5, the other two are attributed to Y2O3:Eu phase and to a particular site on the surface. The occurrence of the latter site may be related to the nanometric size of the sample. A pronounced excitation energy transfer from site 2 to site 1 was also observed on excitation spectra. The energy transfer rate increases rapidly with increasing Eu3+ concentration and for x=0.7 in Y2−xSiO5:Eux, no fluorescence takes place in site 2 at 15 K. The lifetimes of the 5D0 levels of Eu3+ in the two sites were measured as a function of Eu3+ concentration. The results have shown that the lifetime of the 5D0 level of Eu3+ in site 2 decreases with increasing Eu3+ concentration. The energy transfer rate dependence upon temperature was studied in detail and compared to a theoretical simulation. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371246
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Quantized current jumps in silicon photoconductors at room temperature (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3787-3791 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report on the observation of quantized jumps due to single-carrier trapping and detrapping at defect states in silicon photoconductors of 103 μm3 in volume. A specifically designed electrical test structure in a low-doped (2×1014 cm−3) silicon crystal was fabricated. It consists in four substrate resistances connected in a Wheatstone bridge. After the exposure to light, the bridge offset voltage recovers its equilibrium value with steps of 5–10 μV, corresponding to the emission or capture of a single carrier. Such structures also display random telegraph signals in the dark, with steps of similar amplitude. This behavior is observed with structures processed on Czochralski-grown substrates and not with those processed on float-zone substrates. Simple calculations based on quantized free carrier concentration variations corroborate the above measurements. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371288
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Linear electroabsorption in semi-insulating GaAs/AlGaAs asymmetric double quantum wells (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3822-3825 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Electroabsorption has been investigated in semi-insulating asymmetric GaAs/AlGaAs double quantum wells presenting high linear Stark responses, adequate for photorefractive applications. We have used the envelope function approximation to calculate the linear Stark shifts of the energy levels and select a suitable structure for the experimental study. The experimental data indicate that the response to the applied field critically depends on a complicated interplay of effects that compete or cooperate to suppress or enhance the electroabsorption. For positive field polarity, the competing contributions of the overlapping e1–hh1 and e1–hh2 transitions partially cancel the electroabsorption despite large linear Stark shifts. On the other hand, small negative fields induce large electroabsorption because the Stark shifts of the two transitions have opposite signs. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371293
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Simulation studies of persistent photoconductivity and filamentary conduction in opposed contact semi-insulating GaAs high power switches (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3833-3843 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A self-consistent, two-dimensional, time-dependent, drift-diffusion model is developed to simulate the response of high power photoconductive switches. Effects of spatial inhomogeneities associated with the contact barrier potential are incorporated and shown to foster filamentation. Results of the dark current match the available experiment data. Persistent photoconductivity is shown to arise at a high bias even under the conditions of spatial uniformity. Filamentary currents require an inherent spatial inhomogeneity, and are more likely to occur for low optical excitation. Under strong uniform illumination, the spatial nonuniformities were quenched as a result of a polarization-induced collapse in the internal fields. However, strong electric fields resulting at the contacts create a bipolar plasma, and hence, a virtual "double injection." © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371295
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Effect of an electric field on the exciton linewidth due to scattering of excitons by ionized impurities in semiconducting quantum well structures (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4477-4482 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have calculated the effect of an electric field applied along the direction of carrier confinement on the exciton linewidth due to the scattering of excitons by ionized impurities in semiconducting quantum well structures. The contributions to the linewidth due to the elastic and inelastic scattering of the excitons by the ionized impurities have both been taken into account. Both these contributions to the linewidth are found to increase with the applied electric field except for the narrowest wells. However, the linewidth is found to initially decrease with increasing well width for all electric fields and then increase again with increasing well widths for finite electric field for the case where the exciton is scattered elastically. The minimum in the linewidth as a function of well width shifts to smaller well widths with increasing electric field. In the absence of an electric field, the linewidth continues to decrease with increasing well width. When the exciton is ionized as a result of the scattering, the linewidth increases with well width for all nonzero electric fields. However, in the absence of the electric field, the linewidth decreases with increasing well width. This reflects the effect of decreasing confinement on the scattering by ionized impurities. In the case of elastic scattering of the exciton by the ionized impurities, the linewidth has a maximum as a function of the exciton energy with the maximum shifting to lower energies as the well width decreases. For scattering which results in the ionization of the exciton, there is a threshold in the linewidth as a function of the exciton's center of mass energy with the threshold being larger for smaller well widths. The contribution to the linewidth due to elastic scattering of the exciton is many orders of magnitude larger than that due to scattering in which the exciton is ionized. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371390
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Photoinduced surface deformations on azobenzene polymer films (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4498-4508 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Laser-induced surface deformation and surface relief grating formation at different intensity levels on azobenzene-functionalized polymer films were investigated. The surface deformation profile induced by a Gaussian laser beam at low intensities reveals strong polarization dependence and establishes that an optical-field component in the direction of the optical-field gradient is essential for this deformation process. A theoretical analysis based on the optical-field gradient force model is presented to account for the deformation behavior at low intensities. In the higher-intensity regime, however, a different mechanism is found to dominate the surface deformation process. Simultaneous formation of two different types of topographic gratings is observed in a two-beam interference experiment. The phase relationship between these surface relief gratings and the interference intensity pattern was deduced based on the results from the single-beam experiments. The erasing behaviors of the two distinct surface relief gratings were experimentally investigated to highlight the two mechanisms involved in these grating recordings. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371393
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Organic semiconductor heterointerfaces containing bathocuproine (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4515-4519 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The four organic–organic heterointerfaces formed by depositing the organic semiconductor bathocuproine on tris(8-hydroxy-quinoline)aluminum (Alq3), N,N′-diphenyl-N,N′-bis(1-naphthyl)-1,1′ biphenyl-4,4″ diamine (α-NPD), 4,4′-N,N′-dicarbazolyl-biphenyl (CBP), and copper phthalocyanine (CuPc) have been studied using ultraviolet photoelectron spectroscopy. The relative positions of the vacuum levels and highest occupied molecular orbital levels of the organics were measured at each interface. Within our experimental uncertainty of 100 meV, the vacuum levels were found to align at all four interfaces. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371395
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Production and evolution of composition, morphology, and luminescence of microcrystalline arsenic oxides produced during the anodic processing of (100) GaAs (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4997-5003 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: GaAs when exposed to a 7 V anodic bias in aqueous HCl, forms pitted structures from which visible photoluminescence has been observed. Previous work in our laboratory identified the source of the luminescence to be arsenic oxide microcrystals, formed during the electrochemical oxidation, which evolve in composition and morphology during the course of the anodic processing. The density and size of pits is dependent on the solution conditions as well as the applied potential program (stepped vs swept to 7 V. At early times (t〈30 min) the pits are composed of a mixture of small (∼1 μm) and larger (10's of μm) faceted microcrystals identified by x-ray photoelectron spectroscopy and energy-dispersive x-ray analysis to be a combination of As(III) and As(V) oxides. At longer times As(III) oxides predominate, and the smaller microcrystals are no longer observed, suggesting that the smaller microcrystals are As(V) oxide, and that they evolve chemically into As(III) oxide over the course of the oxidation. A suitable reaction pathway which explains the observed predominance of As(III) species is suggested. The luminescence properties of these electrochemically produced structures were investigated by near-field excitation. The luminescent properties evolve in parallel with the morphology and composition although the form of the spectrum is invariant in time and consistent with that obtained from bulk As2O3 and As2O5. The similarity of emission obtained from the two types of microcrystals suggests an impurity-related origin. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371470
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    High resolution measurement of localized-state distributions from transient photoconductivity in amorphous and polymeric semiconductors (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 5026-5035 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The energy resolution of a method for measuring localized-state distributions in amorphous and polymeric semiconductors has been improved in terms of Tikhonov regularization. The method is based on the analysis of transient photoconductivity data using Laplace transforms, and is valid for both pre- and postmonomolecular recombination regimes of the transient photoconductivity. The improvement of the energy resolution is shown using transient photoconductivity data numerically generated from model localized-state distributions appropriate for the materials. In addition, the measurement of localized-state distributions from time-of-flight transient photocurrents is examined. The applicability of the method with improved energy resolution is demonstrated for undoped hydrogenated amorphous silicon, poly(para-phenylene vinylene) and poly(methylphenylsilane). © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371474
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    A study on the oxidation kinetics of silicon in inductively coupled oxygen plasma (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4004-4007 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The oxidation kinetics of silicon in inductively coupled oxygen plasma (ICP) was studied at temperatures ranging from 350 to 450 °C. The oxide growth kinetics was described by a linear-parabolic growth law, with a rapid initial growth and a negative linear-rate constant. Under oxygen pressure of 10 mTorr, the initial oxide growth at 350 °C (thickness below 25 nm) was faster than at 400 °C. An analysis of transverse-optical mode frequencies and etch rates indicated that the density of the surface oxide was lower than that of the bulk oxide. The oxidation kinetics was explained qualitatively by assuming that the ICP oxide consisted of a surface layer with a larger diffusion coefficient and a bulk layer with a smaller diffusion coefficient. On the other hand, the ICP oxidation of silicon with a thin chemical oxide showed a positive linear-rate constant and no surface layer effect, supporting the fact that the oxide grown by the ICP oxidation has a low-density surface layer with a larger diffusion coefficient. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371320
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Coatings for optical pumping cells and extending the lifetime of hyperpolarized xenon (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4040-4042 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We propose evaporative induction heating as a method for the reliable production of coatings for glass cells suitable for the optical pumping and storage of hyperpolarized xenon. The long spin-lattice relaxation times of hyperpolarized xenon-129 contained in cells coated with polyethylene or dotriacontane showed that high quality coatings could be prepared this way. Measurements on cells coated with deuteriated versions of these compounds showed that the expected improvement in performance with isotopic substitution did not occur. This leads to some questions about the level of understanding of wall-induced relaxation in polarization cells. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371325
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Electron ejection from MgO thin films by low energy noble gas ions: Energy dependence and initial instability of the secondary electron emission coefficient (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4049-4051 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Low energy ion-induced secondary electron emission from the surface of thin (500–5000 Å) polycrystalline MgO films has been investigated with various noble gas ions at energies ranging from 45 to 300 eV. The dependence of secondary electron emission coefficient γi on the type and energy of ions is reported and interpreted in terms of electron ejection mechanisms. As-deposited MgO films showed an initial fluctuation in the secondary emission current, which upon annealing or after a certain ion bombardment time irreversibly disappeared. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371328
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Leakage currents in high-quality pulsed-laser deposited aluminum nitride on 6H silicon carbide from 25 to 450 °C (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4052-4054 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The high-temperature dielectric properties of thin-film AlN that were pulsed-laser deposited on a heavily doped n-type 6H–SiC substrate are investigated from 25 to 450 °C. Capacitor leakage current densities of low 10−8 A/cm2 at 25 °C and mid 10−3 A/cm2 at 450 °C are reported for a 1.7 MV/cm dielectric field. The primary high-temperature leakage mechanism appears to be Schottky emission with a zero-field barrier height of 1.76 eV. A dielectric strength in excess of 1.7 MV/cm at 450 °C is reported. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371329
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Optical gain measurements based on fundamental properties and comparison with many-body theory (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 2945-2952 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We present high accuracy measurements of gain, loss, and transparency energy in long-wavelength semiconductors based on a hybrid approach using the fundamental relationship between the gain and the spontaneous emission spectra. Independent measurements of optical gain, transparency energy, and loss show the accuracy and validity of this technique. These results are compared with those obtained by the non-Markovian gain model with many-body effects under the spontaneous emission transformation method. It is found that the hybrid approach for the gain spectrum alleviates many of the problems related to the poor signal to noise ratio in the amplified-spontaneous emission near and below the band edge. The theoretical spectra compare well with the measured spectra for both the transverse electric and transverse magnetic polarizations. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371153
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Coherent, wavelength-tunable ultrasonic acoustic modes stimulated in optical fiber, microcapillaries, and planar microfluidic networks using crossed-picosecond laser pulses (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 2959-2966 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: This article describes the use of optical methods based on picosecond transient gratings to stimulate and detect ultrasonic acoustic modes in several important structures with dimensions less than ∼200 μm: single-mode optical fiber, cylindrical microcapillary tubes, and planar microfluidic networks. The measurements illuminate the characteristics and dispersion of acoustic modes—Rayleigh and Lamb-like modes and Scholte–Stoneley waves—in three-dimensional microsystems with feature sizes that are comparable to the modal wavelengths. The results demonstrate, for example, the ability to measure, rapidly and nondestructively, the mechanical characteristics of on-fiber metal and polymer coatings. They also illustrate real-time monitoring of the elastic and loss moduli, and thermal diffusivities of nanoliter volumes of material contained in planar microfluidic channels during the course of photochemical curing reactions. The techniques are potentially useful for applications ranging from characterization of high-frequency acoustic modes in optical fiber that may be relevant to new types of in-fiber acousto-optic filters and modulators, to detection in microfluidic total analysis systems. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371155
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Erratum: "Modeling the optical constants of HgxCd1−xTe alloys in the 1.5–6.0 eV range" [J. Appl. Phys. 85, 2854 (1999)] (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4713-4713 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371526
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Alignment of cholesteric liquid crystals using periodic anchoring (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3508-3511 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Previous work has shown that when short-pitch cholesteric liquid crystals are aligned in cells with the helical axis in the plane of the substrate in a well-defined direction, then application of an electric field across the cells may result in microsecond in-plane switching due to the flexoelectric effect. Moreover, the response to the electric field is linear and temperature independent. Hence this device geometry has great potential since fast, temperature-independent switching with analogue gray scale may be realized. Up to now, however, the alignment of the helix in the plane of the substrate achieved, for example, by rubbed polyimide layers has been rather unstable, since it relaxes to a Grandjean texture in a time scale determined by the cell thickness. This time is generally of the order of minutes. Here we report a method for the attainment of stable anchoring of the unidirectional lying helix texture using periodic anchoring conditions. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371249
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Comment on "Monte Carlo simulation of the laser-induced plasma plume expansion under vacuum: Comparison with experiments" [J. Appl. Phys. 83, 5075 (1998)] (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 4709-4710 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An attempt to use direct simulation Monte Carlo (DSMC) method for pulsed laser ablation at laser fluence as high as 17 J/cm2 is analyzed. Under these conditions, however, the evaporation flux is very high which results in a very high laser plume density. Therefore, both collision rate and collisional zone near the target are too large to effectively use a conventional DSMC technique whose possibilities are always limited by finite computer storage and available computation time. Nevertheless, the authors of the considered paper claim to propose a new approach to overcome the restrictions of DSMC. We found that the main idea of the approach is the plume reduction in space. However, according to the dimension theory, under this transformation one should preserve the Knudsen number, that defines the degree of rarefaction, and, hence, the number of cells to be used in DSMC. Therefore, the number density of the plume should be increased and particle collisions should be calculated with higher frequency than in the case without space reduction. In our opinion, this important point was neglected by the authors, the collision frequency was not increased, and the number of cells was not properly chosen. As a result, the proposed approach does not break the DSMC restrictions, and the results obtained do not correspond to the experiments with high evaporation flux. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371430
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Observation of lossless radiative modes of a dielectric sphere (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3694-3698 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A theoretical investigation of plane-wave electromagnetic scattering in active dielectric sphere predicted the existence of anomalous resonances that occur at discrete wavelengths. These resonances may be understood from a leaky wave phase matching boundary conditions, in which the gain in the dielectric exactly makes up for the radiative loss of a mode. This results in a radiative mode that does not decay in time, therefore it is described as a lossless radiative mode. Experiments have been performed to verify the existence of these resonances. Optical pumping was used to provide the gain, and the threshold of each resonant mode was found to be a function of the dye concentration and the radius of the dielectric sphere. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371280
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Built-in electric-field effects in wurtzite AlGaN/GaN quantum wells (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3714-3720 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: AlGaN/GaN quantum well (QW) structures are grown on c-plane sapphire substrates by molecular beam epitaxy. Control at the monolayer scale of the well thickness is achieved and sharp QW interfaces are demonstrated by the low photoluminescence linewidth. The QW transition energy as a function of the well width evidences a quantum-confined Stark effect due to the presence of a strong built-in electric field. Its origin is discussed in terms of piezoelectricity and spontaneous polarization. Its magnitude versus the Al mole fraction is determined. The role of the sample structure geometry on the electric field is exemplified by changing the thickness of the AlGaN barriers in multiple-QW structures. Straightforward electrostatic arguments well account for the overall trends of the electric-field variations. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371241
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Optical characterization of low-energy electron-beam-colored LiF crystals by spectral transmittance measurements (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3745-3750 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The complex refractive index of a LiF crystal surface layer irradiated by low-energy electrons is modified by the stable formation of color centers embedded in it. A simplified dipole-electromagnetic field interaction model has been adopted in order to estimate the dispersion curves of colored LiF from a single optical transmittance measurement. The excellent agreement with the corresponding experimental curves (obtained by means of spectrophotometry and ellipsometry) demonstrates this to be a promising approach for LiF-based optical waveguide characterization.© 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371245
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Band-gap and k.p. parameters for GaAlN and GaInN alloys (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3768-3772 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Using a semi-empirical pseudopotential method, a set of band-structure calculations are performed on a range of GaInN and GaAlN alloys in both the zinc-blende and wurtzite structures. Pseudopotentials for the bulk materials are described by suitable V(q) functions, and these are used to construct the alloy pseudopotentials. The band gap as a function of alloy composition is studied, and it is found that there is no significant bowing in the case of GaAlN. The bowing is larger for GaInN, although heavily dependent on the strain present. A more detailed study of the wurtzite alloys is carried out for low Al and In fractions. Wurtzite k⋅p parameters for several alloys at concentrations commonly used in devices are obtained from the semi-empirical band structure using a Monte Carlo fitting procedure. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371285
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Time-resolved four-wave mixing signal in thick bulk GaAs (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3159-3164 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We experimentally demonstrate that the temporal shape of the four-wave mixing (FWM) signal in thick semiconductors is significantly influenced by the absorption of the generated FWM signal during its propagation through the sample as well as the pulse broadening effect, by performing the time-integrated (TI) and time-resolved (TR) FWM experiments, and by measuring the pulse shape of the transmitted probe beam in the presence of a pump beam for a 500- and a 100-μm-thick undoped GaAs. We find that the temporal shape of the TR-FWM signal in the vicinity of the exciton resonance depends on the sample thickness and time delay between two incident pulses. As the excitation laser is tuned far below the exciton resonance, however, the propagation effect of the FWM signal itself through the sample becomes dramatically weaker and the temporal shape of the FWM signal resembles the distorted probe pulse shape. Furthermore, the peak intensities of the TI- FWM signals near the exciton resonance are smaller in the thicker sample than in the thinner sample, whereas in the thick sample are larger well below the exciton resonance, due to the absorption of the FWM signal. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371183
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Electronic properties of light-induced recombination centers in boron-doped Czochralski silicon (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3175-3180 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In order to study the electronic properties of the recombination centers responsible for the light-induced carrier lifetime degradation commonly observed in high-purity boron-doped Czochralski (Cz) silicon, injection-level dependent carrier lifetime measurements are performed on a large number of boron-doped p-type Cz silicon wafers of various resistivities (1–31 Ω cm) prior to and after light degradation. The measurement technique used is the contactless quasi-steady-state photoconductance method, allowing carrier lifetime measurements over a very broad injection range between 1012 and 1017 cm−3. To eliminate all recombination channels not related to the degradation effect, the difference of the inverse lifetimes measured after and before light degradation is evaluated. A detailed analysis of the injection level dependence of the carrier lifetime change using the Shockley–Read–Hall theory shows that the fundamental recombination center created during illumination has an energy level between Ev+0.35 and Ec−0.45 eV and an electron/hole capture time constant ratio between 0.1 and 0.2. This deep-level center is observed in all samples and is attributed to a new type of boron–oxygen complex. Besides this fundamental defect, in some samples an additional shallow-level recombination center at 0.15 eV below Ec or above Ev is found to be activated during light exposure. This second center dominates the light-degraded carrier lifetime only under high-injection conditions and is hence only of minor importance for low-injection operated devices. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371186
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Charge carrier mobility in electroluminescent alternating block copolymers (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3181-3186 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have investigated charge transport in two electroluminescent block copolymers, poly(1,8-octanedioxy-2,6-dimethoxy-1,4-phenylene-1,2-ethenylene-1,4-phenylene-1,2-ethenylene-3, 5-dimethoxy-1,4-phenylene) and poly(1,8-octanedioxy-2,6-dimethoxy-1,4-phenylene-1,2-ethenylene-1,4-phenylene-1,2-ethenylene1,4-phenylene-1,2-ethenylene-3,5-dimethoxy-1,4-phenylene), using current versus voltage measurements performed on metal/polymer/metal structures. The effective mobility of holes has been determined for both polymers. The characteristic charge carrier trap distribution energies of the polymers for the case of Al electrodes have also been determined. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371237
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Single-electron tunneling through Si nanocrystals dispersed in phosphosilicate glass thin films (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3199-3203 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Electrical transport properties of extremely thin phosphosilicate glass (PSG) films containing Si nanocrystals (nc-Si) a few nanometers in diameter were studied. Samples were prepared by cosputtering Si and PSG targets, and post annealing. Periodic Coulomb staircases were clearly observed in the dc current–voltage (I–V) characteristics along the vertical direction of films. Although the step structure was broadened with increasing the temperature, it remained up to 200 K. The I–V curve could be well fitted by Monte Carlo simulation with a simple double-barrier structure model. Advantages of using PSG instead of SiO2 as surrounding matrices of nc-Si to observe single-electron tunneling effects are discussed. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371189
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Electronic states and effective negative electron affinity at cesiated p-GaN surfaces (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3209-3212 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The electronic structure of, and the effects of cesium (Cs) and oxygen (O) adsorption on, the p-GaN(001) surface are investigated via photoemission spectroscopy. Bulk- and surface-sensitive photoemission measurements, and oxygen exposure of clean surfaces, demonstrate the existence of filled surface states which extend ∼0.6 eV above the valence band maximum. The valence band maximum measured after the removal of the surface states gives a downward band bending and electron affinity equal to 1.2±0.2 and 3.3±0.2 eV, respectively. The surface dipole layer induced by exposure to oxygen followed by Cs deposition lowers the vacuum level by 2.8±0.3 eV with respect to the valence and conduction band edges. Under these conditions, the vacuum level is approximately 0.7 eV below the conduction band minimum of the bulk, corresponding to the effective negative electron affinity at this surface. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371191
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Excess silicon at the silicon nitride/thermal oxide interface in oxide–nitride–oxide structures (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 3234-3240 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The chemical composition and structure of Si3N4/thermal (native and wet) SiO2 interface in oxide–nitride–oxide structures are studied by using secondary ion mass spectroscopy, electron energy loss spectroscopy (EELS) and Auger electron spectroscopy (AES) measurements. EELS and AES experiments show the existence of excess silicon at the Si3N4/thermal SiO2 interface. Excess silicon (Si–Si bonds) at Si3N4/SiO2 interface exists in the form of Si-rich silicon oxynitride. Numerical simulation of the Si–Si bond's electronic structure by using semiempirical quantum-chemical method (MINDO/3) shows that Si–Si defects act as either electron or hole traps. This result explains the abnormally large electron and hole capturing at this interface reported earlier. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371195
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...