Preparation and Properties of AlSb-GaSb Solid Solution Alloys

Abstract

Ingots of the quasi-binary GaSb-A1Sb alloy were prepared by progressive casting and zone casting at various rates of crystallization. Results of x-ray diffraction studies, metallographic studies, hardness determinations, and chemical analyses indicate that, with the possible exception of a narrow composition range between 10 and 30 mole % A1Sb which was not investigated, solid solution prevails in the system. Bulk specimens of single phase, solid solution alloy were obtained by use of low linear rates of crystallization (0.05 in./hr), while at higher rates of crystallization (1/a to 1z/4 in./hr) two intermingled solid phases were characteristically obtained.Vegard's law was found to be at least roughly applicable; with lattice constants for the alloys ranging between values of 6.0963A for pure GaSb and 6.1361A for pure A1Sb. Optical energy gaps determined for alloy specimens increased regularly with cell size from a value of 0.68 ev for GaSb to a value of 1.74 ev for A1Sb. Values of electrical resistivity and hole mobility for the relatively impure alloy specimens were also intermediate between those for the compounds in a like state of purity.Liquidus data are also presented for the system.

Growth and Characterization of Al x Ga1 − x Sb

“…For high A1Sb concentration these data for energy gap fall below the corresponding ones in the present work. This may be because alloys prepared by this method (10) show a decrease in the A1Sb concentration as the solidification process proceeds, possibly since the A1 has a higher distribution coefficient than…”

AlxGa1–xSb Crystals Grown by a Modified Stepanov Technique with an Ultrasonic Effect

“…Additionally, the Al concentration decreases to the final part of the Al x Ga 1– x Sb crystal due to an Al segregation coefficient larger than 1. This is confirmed by a GaSb–AlSb pseudobinary phase diagram. , Bischopink and Benz developed growth conditions and grew Al x Ga 1– x Sb single crystals ( x = 0.06–0.65) with up to 24 mm diameter and 28 mm length by the traveling heater method. , The Al concentration decreased and increased in the initial region (5–6 mm) of these crystals. Striations and microscopic inhomogeneity of Al were also observed up to x = 0.01 .…”

“…Al x Ga 1– x Sb crystals are solid solutions with unlimited solubility, the composition of which can change continuously from GaSb to AlSb. − Therefore, the band gap in these solid solutions can smoothly change from 0.72 to 1.615 eV. , Semiconductor crystals with such a band gap are promising materials for high-speed electronics and optoelectronics devices in the spectral region from 1.3 to 6.5 μm. − A small difference in the lattice parameters for AlSb (6.136 Å) and GaSb (6.095 Å) assumes low internal stress in Al x Ga 1– x Sb solid solutions, which can promote a high perfection of their single crystals. ,, However, the considerable difference in density and segregation coefficients of Al and Ga is a major difficulty in the crystal growth of Al x Ga 1– x Sb single crystals. Al atoms and clusters, having a lower density in the Al–Ga–In melt, rise to the melt surface and create a high inhomogeneity in the grown crystal.…”

“…This is confirmed by a GaSb−AlSb pseudobinary phase diagram. 1,2 Bischopink and Benz developed growth conditions and grew Al x Ga 1−x Sb single crystals (x = 0.06−0.65) with up to 24 mm diameter and 28 mm length by the traveling heater method. 12,13 The Al concentration decreased and increased in the initial region (5− 6 mm) of these crystals.…”

Experiments and Calculation of the Al‐Ga‐Sb Ternary Phase Diagram

“…Several authors (5)(6)(7)(8) also reported the Ga-rich corner of the ternary phase diagram which supplied sufficient information required for the growth of lattice matched ternary layers on GaSb substrates. All of their liquidus and solidus data were experimentally determined below 60O~ The absence of phase separation in the GaSb-A1Sb quasi-binary phase diagram was reported by several authors (9)(10)(11).…”