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
  • 1
    Electronic Resource
    Electronic Resource
    Diamond nanocrystals formed by direct implantation of fused silica with carbon (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 90 (2001), S. 3007-3018 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report synthesis of diamond nanocrystals directly from carbon atoms embedded into fused silica by ion implantation followed by thermal annealing. The production of the diamond nanocrystals and other carbon phases is investigated as a function of ion dose, annealing time, and annealing environment. We observe that the diamond nanocrystals are formed only when the samples are annealed in forming gas (4% H in Ar). Transmission electron microscopy studies show that the nanocrystals range in size from 5 to 40 nm, depending on dose, and are embedded at a depth of only 140 nm below the implanted surface, whereas the original implantation depth was 1450 nm. The bonding in these nanocrystals depends strongly on cluster size, with the smaller clusters predominantly aggregating into cubic diamond structure. The larger clusters, on the other hand, consist of other forms of carbon such as i-carbon and n-diamond and tend to be more defective. This leads to a model for the formation of these clusters which is based on the size dependent stability of the hydrogen-terminated diamond phase compared to other forms of carbon. Additional studies using visible and ultraviolet Raman Spectroscopy, optical absorption, and electron energy loss spectroscopy reveal that most samples contain a mixture of sp2 and sp3 hybridized carbon phases. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1388857
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    In situ YBa2Cu3O7−x superconductor films on GaAs/AlAs superlattices (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 5108-5110 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Superconducting YBa2Cu3O7−x films have been deposited in situ onto III-V superlattice substrates. The substrates were GaAs/AlAs superlattices grown by molecular beam epitaxy onto GaAs substrates. For 5000-A(ring) -thick YBCO films grown at 615 °C substrate temperature, we have obtained Tc of 73 K. For thinner films the Tc's are lower, indicating poor interfaces. However, the onset of the superconducting transition is 90 K in all cases. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy (TEM) show these films to be polycrystalline. TEM shows an interaction layer of about 1000 A(ring) at the interface. Low-temperature cathodoluminescence measurements of the substrate show that atomic interdiffusion has intruded at least 5000 A(ring) below the interface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.349020
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Electron field emission from Ti-containing tetrahedral amorphous carbon films deposited by filtered cathodic vacuum arc (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 6842-6847 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Titanium-containing tetrahedral amorphous carbon (ta-C:Ti) films with different titanium content were deposited by a filtered cathodic vacuum arc technique. The microstructure of these films was confirmed to be of ta-C+TiCx(x〈1) nanocomposite by Rutherford backscattering spectroscopy, x-ray diffraction, and micro-Raman spectroscopy experiments. With the increase of titanium content, the titanium carbide content increased and the sp3 fraction in the residual ta-C phase decreased gradually. In the electron field emission tests, it was found that proper conditioning processes are necessary for all these films in order to get a steady reproducible emission behavior. After conditioning, the emission threshold field of the films is about the same value, around 10 V/μm, except for the film with the lowest titanium content (∼1.2 at%) of which the threshold field is much higher, around 17–18 V/μm. The optimum titanium concentration in the film for field emission, showing the highest emission current and emission site density, is about 12 at%. After field emission testing, graphitization was involved and the titanium carbide phase, at least some of the sub-stoichiometric TiCx phase, in the ta-C:Ti films decomposed. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1323541
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Catalyzed growth of carbon nanoparticles by microwave plasma chemical vapor deposition and their field emission properties (2002)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 433-436 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Carbon nanoparticles were prepared from H2 and CH4 by microwave plasma chemical vapor deposition at various temperatures as low as 250 °C by using nickel and iron as catalysts. The carbon nanoparticles are well graphitized until a temperature as low as 400 °C, and the degree of graphitization increases with increasing growth temperature. Field emission measurements showed that the carbon nanoparticles are excellent electron field emitters, comparable to carbon nanotubes. Field emission properties became better with increasing growth temperature, and the threshold fields of the carbon nanoparticles deposited at 400, 500, 670 °C, were 3.2, 3, and 1 V/μm, respectively. No emission was observed for the carbon nanoparticles deposited below 400 °C. The low threshold field of the carbon nanoparticles is attributed to field enhancement effect and the higher degree of graphitization. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1419212
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Carbon nanotube films prepared by thermal chemical vapor deposition at low temperature for field emission applications (2001)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 79 (2001), S. 1670-1672 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Mirror-like smooth carbon nanotube (CNT) films were grown by thermal chemical vapor deposition on glass substrate at a relatively low temperature of 570 °C. Cobalt-containing amorphous carbon composite films were employed as a catalyst layer for the growth of CNTs by decomposing acetylene in a tube furnace. The diameter of the CNTs was around 10 nm and the root-mean-square roughness of the film was about 12 nm, indicating a relatively smooth surface. A high emission current density of 12 mA/cm2 and relatively uniform emission sites were obtained from this type of CNT films. The relatively smooth CNT films, which can be deposited at low temperature on glass substrates and compatible with current semiconductor processes, have a potential for fabricating high-density gated CNT field emitter array. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1391397
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Field emission from cobalt-containing amorphous carbon composite films heat-treated in an acetylene ambient (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 77 (2000), S. 2021-2023 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Cobalt-containing amorphous carbon composite films have been prepared by the filtered cathodic arc technique using a cobalt-containing graphite target at room temperature. After heat treatment at 550 °C in a mixture of acetylene and nitrogen gases, the field emission properties were significantly improved. A threshold electric field of 1.7 V/μm and an emission site density of 105/cm2 were obtained without conditioning. The composite films, which can be deposited with a high rate at room temperature and require a relatively low temperature heat-treatment process to enhance electron emission, are promising for practical applications in field emission display. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1313252
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Localized two-dimensional electron gas formation by focused Si ion beam implantation into GaAs/AlGaAs heterostructures (1990)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 57 (1990), S. 2259-2261 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have demonstrated the localized formation of a two-dimensional electron gas (2DEG) using focused Si ion beam implantation (100 keV) into undoped GaAs/AlGaAs heterostructures. We found that to achieve a good-quality 2DEG without also forming a 3DEG it is essential to use a double instead of a single interface heterostructure. The low-temperature mobility of the 2DEG was as high as 1.0×104 cm2/V s at a carrier concentration of 1×1012 cm−2. This 2DEG mobility in the double heterostructure was a factor of 3 larger than the 2DEG mobility in the single heterostructures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.103908
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Lateral band gap modulation by buried stressor structures in III–V compounds semiconductor quantum-well structures (1992)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 60 (1992), S. 586-588 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A buried stressor structure was fabricated using in situ focused ion beam sputter etching and molecular beam epitaxy to produce a lateral band gap modulation in GaAs/AlGaAs quantum-well structures. Strain induced band gap modulation and the consequent carrier confinement were demonstrated by low temperature cathodoluminescence. A 12 meV deep potential well was demonstrated. The observed band gap shrinkage as a function of distance from the stressor was obtained and is found in good agreement with the theory.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.106589
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Electron beam irradiation enhancement of Al-Ga interdiffusion at GaAs/AlGaAs quantum well interfaces (1990)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 57 (1990), S. 472-474 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The effect of room-temperature electron beam irradiation on the Al-Ga interdiffusion at GaAs/AlGaAs quantum well heterointerfaces is investigated with low-temperature cathodoluminescence spectroscopy. The interdiffusion is enhanced by defects generated through an irradiation with a 400 keV electron beam. After room-temperature irradiation with a dose of ∼1.5×1017–2.5×1017/cm2 and subsequent rapid thermal annealing at 900 °C for 1 min, an interdiffusion length of 3–5 A(ring) is obtained. The electron beam induced damage tends to saturate with increasing irradiation dose, and the formation of defect cluster at high dose limits the defect introduction and, thus, the interdiffusion at the interface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.103669
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Crystal and molecular structure of W(CCMe"3)(PMe"3)"3Cl"3; a seven-coordinate tungsten(VI) alkylidyne complex with a regular capped octahedral (C"5"v) stereochemistry
    Amsterdam : Elsevier
    Journal of Organometallic Chemistry 282 (1985), S. 239-246 
    Details
    ISSN: 0022-328X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0022-328X(85)87174-6
    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...