ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 6251-6255 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Epitaxial PtSi/p-Si(100) contacts were fabricated by co-depositing Pt and Si on p-Si(100) at 450 °C in a dual electron gun chamber at a base pressure of 10−10 Torr. The PtSi/p-Si(100) film possessed six types of epitaxial modes, as indicated in the electron diffraction patterns. The average grain size of the PtSi grains was measured to be 100–300 A(ring) through the Moiré fringe image. The Schottky barrier height of the epitaxial PtSi/p-Si(100) diode was determined to be 0.249 eV at 100 K, with an ideality factor of 1.04. In contrast to this, the Schottky barrier height of the polycrystalline PtSi/p-Si(100) diode was 0.229 eV at 100 K, with an ideality factor of 1.05. The difference in Schottky barrier height was attributed to the difference in the atomic arrangement at interface.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 394-399 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Raman scattering has been carried out on PbTiO3 thin films prepared on platinum-coated (100) silicon by radio-frequency (rf)-magnetron sputtering without substrate heating and a post-deposition thermal treatment. The Raman spectra obtained from the thin film are characteristic of powder Raman spectra: In comparison with the single crystal spectra, the intensity of the background is relatively high at low frequencies and the Raman lines are broad. The lattice phonon modes corresponding to the observed lines are identified by comparison with the data on single crystals and powder. The Raman frequencies for the thin film remarkably shift to low frequencies compared with single-crystal data. It is shown that the phenomenon of the frequency shifts is similar with the hydrostatic pressure effect on single crystals of PbTiO3. The result indicates that the thin films are composed of grains that are stressed depending on the grain size by neighboring grains of different orientations when they are split up into ferroelectric domains at the paraelectric-to-ferroelectric transition. This stress effect is significant even for a grain size of ∼0.5 μm. It is found that the lowest frequency E transverse optical (TO) mode in the thin film shows softening with increasing temperature as was reported in previous studies on single crystals.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 536-538 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Having been exposed to hydrogen plasma, Te-doped GaAs wafers were deposited with metal Ti, to form Ti/n-GaAs Schottky barrier diodes (SBD). It was found that due to hydrogenation the Schottky barrier height (SBH) of the SBD decreases from 0.76 to 0.58 eV and the effective Richardson constant A** decreases from 11 to 0.03 A/cm2/K2. Annealing the hydrogenated SBD at different reverse biases at 100 °C produces SBHs that have a one-to-one correlation with the biases of reverse-bias annealing (RBA), i.e., the SBH can be controlled, within the range 0.58–0.74 eV, by the bias of RBA. When the reverse bias is equal to or larger than 3 V, the SBH and the effective Richardson constant of the hydrogenated SBDs after RBA are very near to those of SBDs without hydrogenation. This means that a RBA with a bias higher than a critical value, 3 V in our case, can remove the effects of hydrogenation, but if the SBD is annealed again without a bias at 100 °C for 1 h or more, its SBH and effective Richardson constant recover their hydrogenated values. The main experimental facts can be explained qualitatively by a simple theoretical model.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 6146-6149 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The crystallization of a mechanically alloyed Sm-Fe alloy was investigated. The results show that the Sm-Fe alloy prepared by mechanical alloying consists of amorphous Sm-Fe phase and crystalline α-Fe phase. The composition of the alloy is inhomogeneous, i.e., the surface of the as-milled powder is relatively poor in iron. The crystallization process involves the long-range diffusion of iron atoms and solid state reaction. After proper crystallization, the as-milled powder transforms into a Sm2Fe17 phase completely; no distinguishable crystalline α-Fe phase can be found. A metastable phase, which may be a Sm2Fe17 phase with the structure of hexagonal Th2Ni17 type, appears during the crystallization process.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 6625-6631 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Raman scattering is used to characterize thin films of PbTi1−xZrxO3. The films have been prepared on platinum-coated (100) silicon by radio-frequency (rf)-magnetron sputtering without substrate heating followed by a post-deposition annealing at 600–650 °C. As the concentration of Zr is increased, the Raman peaks broaden and their intensities decrease more rapidly compared with bulk ceramic or powder samples, while the background intensity increases. The observations show that the crystal structure of the films is locally deformed and significantly disordered. With increasing x, the soft E(TO) mode shifts to lower frequencies. An additional Raman peak appears besides the phonon peaks expected in a perfect crystal. The soft mode strongly couples with the extra mode, similarly with the case of ceramic samples. The results are related to features of the thin films such as a frustrated phase transition, i.e., smaller differences between the lattice parameters a and c in comparison with powder data, and an electrical behavior showing a diffuse ferroelectric-to-paraelectric transition with a broad peak.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 8419-8422 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Using an off-axis rf sputtering configuration, we have prepared in situ high-Tc YBa2Cu3O7−y (YBCO) films with a relatively large deposition rate. The sputtering gas was a mixture of Ar and O2 (7:3) and the substrates were MgO(100) and SrTiO3(100). We found that the distance from the target to the substrate, d, is a key factor in the deposition rate. By decreasing d to a value of about 1.5–2.5 cm, we obtained a deposition rate as great as 2000–2500 A(ring) per hour with an rf power of 120 W and at a total pressure 100–200 mTorr. The transport behaviors of the as-grown YBCO films under magnetic fields are reported. The activation energy derived from the resistive transition in magnetic fields is thickness dependent.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 7492-7495 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The microstructures of a highly textured bulk YBa2Cu3 (123) superconductor, with the high-transport Jc (≥ (R18)3.7×104 A/cm2 at 77 K) and flux jumps (T〈15 K), were characterized by x-ray diffraction, polarized optical microscopy, scanning electron microscopy, and scanning transmission electron microscopy. It was found that the grains of the 123 superconductor are preferentially oriented along the a-b plane of the 123 phase. The Y2BaCuO5 and CuO particles are dispersed uniformly in the 123 matrix, and the highly dense twins run through the matrix everywhere. Some irregular-shaped BaCuO2-CuO mixtures were observed at the 123 grain boundaries. The aligned 123 crystals and microstructural defects in the 123 matrix are considered to be responsible for the high-Jc value and flux jumps.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 2731-2733 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The in situ epitaxial growth of the Y-Ba-Cu-O films on MgO (001) was carried out by 40.68- MHz rf magnetron sputtering with an on-axis single target. It appeared that the rf discharge strongly affected film composition, crystallinity, superconductivity, and reproducibility. Highly orientated superconducting films with the c-axis perpendicular to the substrate surfaces and having zero resistance transition temperature of 78.2 K were obtained without a post-annealing.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 68 (1990), S. 958-964 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: First, an overview of the present state of art of imaging of three-dimensional particle (or damage) distributions in the field of ion implantation is given. Usually, the direct measurement of three-dimensional distributions in the field of ion implantation is restricted to cases when the impinging ion beam diameter is small against the size of the corresponding distributions, i.e., to ion energies above typically 100 MeV and to microbeams of a few μm diameter. To gain information also for lower ion energies without the restriction in the beam diameter, a modified tomographic reconstruction technique has been developed recently by us and is described here in detail. Three-dimensional distributions are reconstructed from a number of one-dimensional depth profiles, implanted under various angles. Competing algorithms for the solution are discussed. For the mathematical technique chosen, some consistency tests are presented. Good accuracy of a sufficient number of input profiles is vital for the quality of the three-dimensional reconstruction
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A low-resistance and nonspiking contact consisting of a layered structure of Si/Ni(Mg) on p-GaAs is formed by solid-phase regrowth. Backside secondary-ion mass spectrometry and cross-sectional transmission electron microscopy show an initial reaction between Ni and GaAs to form NixGaAs which is later decomposed to form NiSi by reacting with the Si overlayer. This reaction leads to the solid-phase epitaxial regrowth of a p+ -GaAs layer doped with Mg. The total consumption of substrate is limited to a few hundred angstroms. The as-formed ohmic contact structure is uniform and planar with an average specific contact resistivity of ∼7×10−7 Ω cm2 on substrates doped to 8×1018 cm−3. The thermal stability of this contact scheme is also reported.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...