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7. Critical layer thickness and strain relaxation measurements in GaSb(001)/AlSb structures.

Author

Gossmann, H.-J., Davidson, B. A., Gualtieri, G. J., Schwartz, G. P., Macrander, A. T., Slusky, S. E., Grabow, M. H., and Sunder, W. A.

Subjects
ALUMINUM compounds, GALLIUM compounds, SUPERLATTICES, X-ray diffraction, THIN films
Abstract

Features a study that measured critical layer thicknesses and strain relaxation for aluminum antimony (AlSb) single layers and gallium antimony/AlSb superlattices. Use of ion scattering, x-ray diffraction and Raman scattering; Ways to determine crystalline quality and strain in thin films; Extraction of the angular position of the minima in the angular scans.

Published
1989
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16. X-ray photoemission core level determination of the GaSb/AlSb heterojunction valence-band discontinuity.

Author

Gualtieri, G. J., Schwartz, G. P., Nuzzo, R. G., and Sunder, W. A.

Subjects
VALENCE (Chemistry), GALLIUM compounds, ALUMINUM compounds, HETEROJUNCTIONS
Abstract

The valence-band discontinuity ΔEv has been determined for the (100) GaSb/AlSb strained-layer heterojunction with a room-temperature lattice mismatch of 0.65%, using x-ray photoemission core level spectroscopy. For 30 Å epitaxial layers of AlSb grown on GaSb, the measured valence-band offset was ΔEv=0.40±0.15 eV. The reverse growth sequence consisting of a thin GaSb layer grown on an AlSb buffer exhibited the same valence-band offset, indicating that for the (100) oriented heterojunction ΔEv is not strongly affected by the growth sequence. [ABSTRACT FROM AUTHOR]

Published
1986
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17. Room-temperature operation of optically pumped InGaAsSb/AlGaAsSb double-heterostructure laser at [bar_over_tilde:_approx._equal_to]2 μm.

Author

Dutt, B. V., Temkin, H., Kolb, E. D., and Sunder, W. A.

Subjects
SEMICONDUCTOR lasers, HETEROSTRUCTURES, INDIUM compounds, ALUMINUM compounds
Abstract

Optically induced room-temperature lasing at ...2 µm of the InGaAsSb/AlGaAsSb double heterostructures is reported. The growth of the quaternary antimonide structures lattice matched to GaSb substrates by liquid phase epitaxy is described. The optical thresholds and their temperature dependence are comparable to the InGaAsP devices operating at 1.55-µm wavelength regions. [ABSTRACT FROM AUTHOR]

Published
1985
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21. Mechanics of Damage in Rate-Sensitive Construction Materials

Author

MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF CIVIL ENGINEERING, Sunder, W. S., Wu, Maos, MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF CIVIL ENGINEERING, Sunder, W. S., and Wu, Maos

Abstract

Rate mechanisms govern the mechanical behavior of construction materials under three conditions: 1) at high homologous temperatures; 2) when subjected to short term loading that is quasi-static, impulsive, or vibratory; and 3) when subjected to sustained (or creep) loading over long times. Examples of advanced construction materials satisfying one or more of these conditions include: Polymer matrix structural composites such as FRPs; Single-ply roofing membranes made of elastomers; c) Polycrystalline ice in cold regions engineering; and d) Cementitious composites such as high-strength concretes and FRCs. The deformation and progressive failure of such rate sensitive materials is governed by three primary mechanisms: flow, distributed cracking, and localized crack propagation. The interaction of these mechanisms gives rise to complex mechanical behavior on the macro-scale. The characterization of these mechanisms and their interaction is therefore of fundamental importance. The objective of this research is to develop an understanding of and characterize the rate and damage processes and their interaction in advanced construction materials. This report presents: a multiaxial differential flow model; a rate and pressure sensitive anisotropic damage model; and, specification for testing materials.

Published
1987

35. DIPRIVAH

Author

Fahmy, N. R., primary, Alkhouli, H. M., additional, Sunder, W., additional, Smith, D., additional, and Kelley, M. M., additional

Published
1985
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48. Response to ‘‘Comment on ‘X-ray photoemission core level determination of the GaSb/AlSb heterojunction valence-band discontinuity’ ’’[Appl. Phys. Lett. 50, 1763 (1987)].

Author

Gualtieri, G. J., Schwartz, G. P., Nuzzo, R. G., and Sunder, W. A.

Subjects
HETEROJUNCTIONS, PHOTOEMISSION
Abstract

Responds on the article, entitled 'X-ray photoemission core level determination of the GaSb/AlSb heterojunction valence-band discontinuity,' by Gualtieri and others. Comparison of core level energy differences measured for the heterojunction; Authors' comparison of their results with spectroscopic values from a variety of sources; Relative merits of obtaining the separation from Schottky barrier data.

Published
1987
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