The influence of temperature gradient and lowering speed on the melt-solidinterface shape of GaxIn1-xSb alloy crystals grown by vertical Bridgman technique

Radially homogeneous bulk alloys of GaxIn1-xSb in the range 0.7 < x < 0.8, have been grown by vertical Bridgman technique. The factors affecting the i nterface 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 ampo ule lowering speed (v) was deduced for attaining the planarity of the melt- solid interface. The studies carried out on directional solidification of G a0.77In0.23Sb mixed crystals employing planar melt-solid interface exhibite d superior quality than those with nonplanar interfaces. The solutions to c ertain problems encountered during the synthesis and growth of the compound were discussed. (C) 1999 Elsevier Science B.V. All rights reserved.