Effect of residual gaseous impurities on the dewetting of antimonide melts in fused silica crucibles in the case of bulk crystal growth

A Bridgman set-up has been modified to perform the contactless growth (“dewetting”) of gallium and indium antimonide compounds in fused silica crucibles. According to wetting parameters measured by the sessile drop method given in the literature, both molten InSb and GaSb compounds are considered as non-reactive with silica substrates. A detailed description of the experimental set-up is presented. Each polycrystalline sample is inserted in a sealed silica crucible that is backfilled with industrial argon containing a few ppm of oxygen. Under similar experimental conditions, the dewetted growth of GaSb is much easier to obtain than that for InSb. The presence of residual impurities such as oxygen in the backfilling gas appears to enhance the occurrence of the phenomenon for GaSb.