The influence of temperature gradient and lowering speed on the melt–solid interface shape of Ga xIn 1− xSb alloy crystals grown by vertical Bridgman technique

Abstract

Radially homogeneous bulk alloys of Ga x In 1− x Sb in the range 0.7< x<0.8, have been grown by vertical Bridgman technique. The factors affecting the interface shape during the growth were optimised to achieve zero convexity. From a series of experiments, a critical ratio of the temperature gradient ( G) of the furnace at the melting point of the melt composition to the ampoule lowering speed ( v) was deduced for attaining the planarity of the melt–solid interface. The studies carried out on directional solidification of Ga 0.77In 0.23Sb mixed crystals employing planar melt–solid interface exhibited superior quality than those with nonplanar interfaces. The solutions to certain problems encountered during the synthesis and growth of the compound were discussed.