Strain and critical thickness in GaSb(001)/AlSb.

Measurements of critical layer thicknesses and strain relaxation have been made for AlSb on GaSb(001) using ion scattering/particle induced x-ray techniques. The maximum strain in the films agrees well with that calculated from bulk elesticity data. The critical thickness as measured by the ion channeling experiment is ~140 +- 30angstroms. Films exceeding the critical thickness do not relieve the strain immediately but rather show a gradual relaxation up to ~1000Angstroms.