ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
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
    Facing targets sputtered Fe-N gradient films (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 78 (1995), S. 2596-2600 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Fe-N gradient films were prepared with a facing targets sputtering system. During deposition, the nitrogen pressure increased linearly up to a value, which is called the "ultimate pressure.'' Composition profiles, microstructure, magnetic properties, and corrosion resistance of the films were investigated by various methods. The experimental results indicate that the Fe-N films possess some composition and structural gradients. The Fe concentration decreases from the substrate to the film surface from 100 to 66 at. %. The phases α‘-Fe16N2, γ'-Fe4N, ε-FexN(2〈x≤3) and ζ-Fe2N are present in the gradient films at different depths. Ms under the ultimate nitrogen pressure of 0.05 Pa has a value of 1803 emu/cc which is higher than that of bulk iron, this is attributed to the presence of Fe16N2. Increasing further the ultimate nitrogen pressure, Ms decreases monotonically. The corrosion resistance of the gradient film with higher nitrogen concentration near the surface is good enough for magnetic recording heads. © 1995 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.360119
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Photoluminescence spectroscopy and the effective mass theory of strained (In,Ga)As/GaAs heterostructures grown on (112)B GaAs substrates (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 843-848 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The photoluminescence characteristics of pseudomorphic In0.19Ga0.81As/GaAs quantum well structures grown on both the conventional (001) and the unconventional (112)B GaAs substrate are investigated. It is found that the emission spectra of the structures grown on the (112)B surface exhibit some spectral characteristics not observed on similar structures grown on the (001) surface. A spectral blue shift of the e→hh1 transition with increasing optical pump intensity is observed for the quantum wells on the (112) surface. This shift is interpreted to be evidence of a strain-induced piezoelectric field. A second spectral feature located within the band gap of the In0.19Ga0.81As layer is also observed for the (112) structure; this feature is thought to be an impurity-related emission. The expected transition energies of the quantum well structures are calculated using the effective mass theory based on the 4×4 Luttinger valence band Hamiltonian, and a related strain Hamiltonian. © 1995 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.359009
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Thermal evolution of carbon in annealed Co/C soft x-ray multilayers (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 1428-1436 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The structures of the carbon sublayers in the annealed Co/C soft x-ray multilayers fabricated using a dual-facing-target sputtering system have been characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), and Raman spectroscopy (RS). The results suggest that the structural variations in the carbon layers can be roughly divided into three stages, i.e. ordering, crystalline and grain growth stages. In the ordering stage with annealing temperatures below 400 °C, the upward shift of D and G lines in Raman spectra indicates that the amorphous carbon layers are changing from ones with bond-angle disorder and fourfold-bonding only to ones containing threefold-bonding. In the crystalline stage, the amorphous carbon layers in the as-deposited multilayers crystallize to graphite crystallites in the annealing temperature range of 500–600 °C. The rapid increase in the intensity ratio of D line to G line and dramatic decrease in linewidth further confirm this substantial structural change. In the grain growth stage, the specimens are annealed at temperatures higher than 700 °C. The decrease in the intensity ratio implies a growth in the graphite crystallite dimensions, which is consistent with the XRD and TEM results. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.363010
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Epitaxial single crystal Fe16N2 films grown by facing targets sputtering : The 40th annual conference on magnetism and magnetic materials (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 5440-5442 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: α″-Fe16N2 single crystal films can be prepared successfully by facing targets sputtering directly onto NaCl(100) substrates in a mixture of argon and nitrogen gases. Both x-ray diffractometer and transmission electron microscope are employed to characterize the crystal structure of the films. The perfect electron diffraction patterns of α″-Fe16N2 single crystal in [1¯11], [011], and [001] directions can be distinctly observed by double tilting. These patterns confirm that the crystal structure of the films corresponds to a body-centered tetragonal (bct) lattice with the parameters of a=b=5.72 A(ring) and c=6.29 A(ring) . The x-ray diffraction patterns show that α″-Fe16N2 epitaxially grows on the NaCl(100) substrate with an orientation relationship α″-Fe16N2(001)(parallel)NaCl(001) and α″-Fe16N2[100](parallel)NaCl[100]. The saturation magnetization of the Fe16N2 films is around 2100−2300 emu/cc, which agrees well with the value reported by Sugita et al.. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.361843
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Enhanced hydrogen desorption from Si sites during low-temperature Si1−xGex growth by disilane and solid-Ge molecular beam epitaxy (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 6920-6922 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A phenomenological model is proposed to explain quantitatively the interesting compositional dependence on the Ge incorporation rate during low-temperature growth of Si1−xGex by disilane and solid-Ge molecular beam epitaxy, based on enhanced hydrogen desorption from Si sites due to the presence of Ge atoms. The hydrogen desorption rate constant for disilane on Si sites is fitted to an exponential function of Ge incorporation rate and a possible physical explanation is discussed. Simulated results are in excellent agreement with experimental data. © 1999 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.370106
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Near-field optical beam induced current measurements on heterostructures (1995)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 67 (1995), S. 1862-1864 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We report near-field optical beam induced current (NOBIC) measurements on semiconductor quantum well (QW) structures. A subwavelength fiber tip is coupled with a tunable laser source and scanned over a sample surface. The induced photocurrent reveals the compositional profile of quantum structures. Semiconductor QW structures were designed and fabricated by molecular beam epitaxy (MBE) to study the wavelength dependence and resolution capability of NOBIC. We demonstrated that the resolution of this technique strongly depends on the aperture size. For aperture sizes that allow for coupling of evanescent fields from the tip into the semiconductor as propagating fields, the resolution strongly depends on the excitation wavelength due to the variation of the optical penetration depth. For smaller apertures, the optical field remains evanescent in the semiconductor and resolution is essentially independent of the wavelength. © 1995 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.114357
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Laterally oxidized GaInP/AlGaInP quantum well visible laser diodes (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 82 (1997), S. 2710-2712 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: High efficiency, low threshold visible AlGaInP/GaInP laser diodes using a buried AlAs native oxide for carrier and optical confinement are described. The lasers incorporate a thin AlAs layer in the upper cladding region, which when laterally wet oxidized, forms a narrow aperture. The lasers exhibited modest performance under continuous wave (cw) operation. Low temperature (400 °C) post-fabrication annealing was shown to dramatically improve the device characteristics. The lasers operate with room temperature cw threshold currents of 20 mA with external differential quantum efficiencies of 27% per facet (0.25 W/A per facet) for an uncoated 625-μm-long, 3.5-μm-wide device. © 1997 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.366091
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Dual-wavelength AlGaAs/GaAs laser by selective removal of a quantum well in an asymmetric dual quantum well structure (1996)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 68 (1996), S. 284-286 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The longer-wavelength quantum well in an AlGaAs/GaAs asymmetric dual quantum well laser structure was selectively removed by localized intermixing. High Si doping on each side of the longer-wavelength well caused intermixing during an anneal under a SiNx cap, while leaving the other nearby well intact. During an anneal under an exposed GaAs surface layer, both quantum wells remained intact. By patterning the surface with alternating SiNx and exposed GaAs, the longer-wavelength quantum well was selectively intermixed. Integrated broad area lasers were fabricated with threshold current density and external quantum efficiency of 260 A/cm2 and 30%/facet at a wavelength of 751 nm in capped regions and 195 A/cm2, 32%/facet at 824 nm in the uncapped regions. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.116060
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Red and infrared side by side semiconductor quantum well lasers integrated on a GaAs substrate (1998)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 73 (1998), S. 1793-1795 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We report red and infrared quantum well (QW) semiconductor lasers integrated on a GaAs substrate by etching and regrowth. A separate confinement heterostructure infrared laser containing an In0.15Al0.15Ga0.7As/Al0.4Ga0.6As QW with AlInP cladding layers was grown on a GaAs substrate. The wafer was then patterned with stripes of etch masks and was etched back to the substrate. A Ga0.4In0.6P/(AlGa)0.5In0.5P QW separate confinement heterostructure laser was subsequently grown side by side with the infrared laser structure. Independently addressable dual-wavelength lasers of 50 μm spacing were fabricated by forming 4 μm wide buried ridge waveguides. The dual-wavelength lasers operated in threshold currents of 10 mA at a peak wavelength of 835 nm and 20 mA at a peak wavelength of 670 nm.© 1998 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.122284
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Influence of rapid thermal annealing on the optical properties of gallium nitride grown by gas-source molecular-beam epitaxy (1998)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 72 (1998), S. 936-938 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Raman scattering, photoluminescence (PL), and nuclear reaction analysis (NRA) have been employed to investigate the effects of rapid thermal annealing (RTA) on GaN films grown on sapphire (0001) substrates by gas-source molecular-beam epitaxy. The Raman spectra showed the presence of the E2 (high) mode of GaN and shift of this mode from 572 to 568 cm−1 caused by annealing. The results showed that RTA has a significant effect on the strain relaxation caused by the lattice and thermal expansion misfit between the GaN epilayer and the substrate. The PL peak exhibited a blueshift in its energy position and a decrease in the full width at half maximum after annealing, indicating an improvement in the optical quality of the film. Furthermore, a green luminescence appeared after annealing and increased in intensity with increasing annealing time. This effect was attributed to H concentration variation in the GaN film, which was measured by NRA. A high H concentration exists in as-grown GaN, which can neutralize the deep level, and the H-bonded complex dissociates during RTA. This leads to the appearance of a luminescent peak in the PL spectrum. © 1998 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.120878
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...