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
  • American Institute of Physics (AIP)  (13)
  • 1995-1999  (13)
Collection
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Characterization of GaAs/AlGaAs heterojunction bipolar transistor devices using photoreflectance and photoluminescence (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 6160-6163 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Photoreflectance (PR) and photoluminescence (PL) techniques were used to characterize the AlGaAs/GaAs heterojunction bipolar transistor (HBT) wafers grown by molecular beam epitaxy (MBE). The line shape of the PR GaAs signal is closely related to the cleanliness of the MBE system. The Franz–Keldysh oscillations of the GaAs signal become sharper, well defined, and the oscillation amplitude increases slightly as the MBE system is cleaned up. The dc current gain of the HBT devices was observed to increase accordingly. The origin for this correlation is discussed. The PL spectra of the HBT device wafers indicate that the intensity of the free-to-bound transition corresponding to the donor to valence band becomes strong in high gain device wafers. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371669
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Magnetic properties of sputtered Fe1−xO and Fe+Fe3O4 thin films : The 41st annual conference on magnetism and magnetic materials (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 5250-5252 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An attempt was made to increase saturation magnetization of Fe3O4 films by incorporating α-Fe phase through the decomposition of as-deposited Fe1−xO films, which were dc-sputtered onto Si(100) substrate by controlling the oxygen flow rates to a thickness of 70–400 nm. The as-prepared Fe1−xO films, being ferrimagnetic, show a thickness dependent microstructure and properties. The formation region of the single phase Fe1−xO was worked out as functions of oxygen flow rate and thickness. After vacuum-annealing, the Fe1−xO phase decomposed to Fe+Fe3O4 phases leading to an increase in coercivity from 15 Oe to 520–990 Oe, and an increase in saturation magnetization from 100 to 290–410 emu/cm3 depending on film thickness. The nanostructure of as-prepared and annealed films were examined by a high resolution transmission electron microscope, the former does not show well defined grain boundaries, while the later has well defined grains, 20–50 nm in size. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.364483
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Nanocomposite Sm2Co17/Co permanent magnets by mechanical alloying : The 40th annual conference on magnetism and magnetic materials (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 5964-5966 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Mechanically alloyed magnets SmCox (x=6.0–11.0) have been prepared using starting materials of commercial SmCo5 and Co powders. X-ray diffraction data indicate that the equilibrium Sm2Co17 phase can be achieved in a nanocomposite Sm2Co17/Co system at x=8.5–11.0, while a Sm2Co17/SmCo5 structure occurs at x=6.0–8.0. The best magnetic properties obtained at x=10.0 are as follows: (BH)max=10.2 MGOe, Br=9.4 kG, Hc=4.0 kOe, and S=0.82. Wohlfarth's remanence analysis indicates that the high remanence can be attributed to the intergranular interaction between neighboring cobalt and Sm2Co17 grains. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.362121
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Stress effect on coercivity of γ-Fe2O3 thin films (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 1184-1188 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Thin Fe3O4 films were deposited in situ on Si(100) substrates by dc-reactive magnetron sputtering method, and then γ-Fe2O3 thin films were obtained by post-oxidation treatment. The effect of residual stress on coercivity of these films was studied by a bending-beam method. In situ stress-temperature curves of the films taken during the whole heat treatment processes revealed the magnitude and state of film stresses. The measured coercivity increments (470 Oe) are very close to the value (460 Oe) calculated based on stress-induced anisotropy for films with pure γ-Fe2O3 phase. For a film with mixed Fe3O4 and γ-Fe2O3 mixed phase, the magnetostriction is calculated to be 17×10−6. In situ stress-temperature data are provided to depict phase transformations and stress effects on the coercivity of such films. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.358983
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Electrical characteristics of nearly relaxed InAs/GaP heterojunctions (1997)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 70 (1997), S. 1551-1553 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The electrical properties of lattice mismatched InAs/GaP heterojunctions are examined. In spite of a high dislocation density at the heterointerface, the current versus voltage characteristics show nearly ideal behavior with low reverse leakage currents and high breakdown voltages. The forward current varied exponentially with bias displaying ideal factors of 1.10 or less. Band offsets estimated from current–voltage and capacitance–voltage analysis are consistent with previous estimates based on differences in Schottky barrier heights. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.118614
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Use of annealed low-temperature grown GaAs as a selective photoetch-stop layer (1996)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 68 (1996), S. 1678-1680 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We demonstrate annealed low-temperature grown (LTG) GaAs to be a highly effective etch-stop layer while photoetching n-type normal-growth-temperature GaAs. During this process, the etch rate is controlled by the transport of photogenerated carriers to the semiconductor/electrolyte interface. Because of the very short minority carrier lifetime in LTG-GaAs, only a very small portion of photogenerated carriers can reach the semiconductor surface to complete the electrolytic decomposition reaction. Therefore, the etch rate of LTG-GaAs is reduced considerably. In our studies, the etch rate selectivity can be as high as 800. Furthermore, we demonstrate that doping concentration, presence of an ohmic contact, photon energy, and pH value of the etching solution can be used to control the etch rate of n-GaAs during the photoetching process. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.115903
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Magnetization reversal of Nd(Dy)–Fe–B thin films on Si(111) or Ta/Si(111) : The 7th joint MMM-intermag conference on magnetism and magnetic materials (1998)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 83 (1998), S. 6241-6243 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Nd(Dy)–Fe–B films were prepared by dc magnetron sputtering on a Si(111) wafer with or without a Ta underlayer. The reversal magnetization process of Nd–Fe–B/Ta bilayer was found to be dominated by nucleation control model with the magnetic inhomogeneity coefficient αk=0.32 defined by Kronmuller's formulation of micromagnetic theory. But the coercivity mechanism of Nd(Dy)–Fe–B single layer was fitted well to domain wall pinning behavior. The range factor (half width between pinning sites) r0 is equal to 6.9 nm as r0〉δB, the width of the domain wall. The magnetization phenomena of the two films are also manifest from initial magnetization curves. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.367770
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Alternating current susceptibility study of a two-phase nanocomposite Fe88Nd6B6 alloy in the temperature range 77–990 K (1998)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 83 (1998), S. 3731-3737 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Alternating current-initial susceptibility (χac) studies on as-spun amorphous and rapid-thermal-annealed two-phase nanocomposite Fe88Nd6B6 alloy ribbons are performed at 77–990 K. A novel means of quantitatively estimating the amount of the residual amorphous phase in heated ribbons is also derived from the χac measurement. Experimental results indicate that the amount of the residual amorphous phase decreases with an increasing heating temperature. The residual amount is 28.87 vol % after the amorphous ribbons are heated to 773 K, and then becomes undetectable when the temperature reaches heating to 923 K. The amount of the residual amorphous phase can be described as follows: R (in vol %)=0.857T/(T–753)–4.392, where T denotes the heating temperature above 753 K. In addition, the full width at half-maximum of the χac peak corresponding to the Curie temperature of the Nd2Fe14B phase correlates well with the extent of exchange coupling interaction between the hard and soft nanophases. Furthermore, the spin reorientation transition temperature of the Nd2Fe14B nanophase in the two-phase nanocomposite Fe88Nd6B6 alloy shifts to 110 K, i.e., significantly lower than 135 K for the Nd2Fe14B single crystal. This shift is attributed to the exchange coupling effect between the nanophases. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.366599
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Very low resistance nonalloyed ohmic contacts using low-temperature molecular beam epitaxy of GaAs (1995)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 66 (1995), S. 1412-1414 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Ex situ nonalloyed ohmic contacts were made to n- and p-type GaAs using low-temperature molecular beam epitaxy. For n-type GaAs, Ag, and Ti/Au nonalloyed contacts displayed specific contact resistitivities of mid 10−7 Ω cm2. For p-type GaAs, nonalloyed Ti/Au contacts with specific contact resistivities of about 10−7 Ω cm2 were obtained. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.113218
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Impact ionization coefficients in (100) GaInP (1995)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 66 (1995), S. 3507-3509 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Electron and hole impact ionization coefficients in (100)Ga0.5In0.5P have been measured by photomultiplication measurements. The ratio of hole to electron ionization coefficients, β/α, is shown to decrease from 2 to 1 when the electric field is increased from 3.5×105 to 6.5×105 V/cm. As confirmation, breakdown voltages were measured for several p+−n−−n+ diodes with various concentrations in the n− region. The values observed showed good agreement with those calculated from the ionization coefficients. Typical breakdown voltages are on the order of 1.6 times higher than those expected for GaAs. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.113779
    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...