Thermodynamic stability and reactivity of AlSb and their relationship to crystal growth.

The vapor pressure, species concentration and reactivity of AlSb is modeled thermodynamically using the newly-described sticky trust region technique, STRT, for free energy minimization. The conditions chosen include oxygen and hydrogen concentrations appropriate to Czochralski crystal growth in SiO sub 2, C, BN, Al Sub 2 O sub 3 and BeO crucibles and growth in the absence of a crucible. Results are compared with crystal growth experiments where appropriate. At the melting point the principal vapor species is Sb sub 2 with a total vapor pressure of ~10 sup (-3) atm., which is about 10 sup 2 larger than for GaSb. These results agree with the experimental data of Sirota and Golodushko. Reaction with the crucible is predicted for SiO sub 2 and BN, in agreement with crystal growth experiments, and also with C, but the slow kinetics of vitreous carbon reactions make it possible to use it for crucibles. Al sub 2 O sub 3 and BeO are predicted to be inert. Preliminary crystal growth results confirm these results and these materials are recommended for further investigation. The results indicate that thermodynamic "testing" of crucibles is an appropriate crystal growth strategy.