Constitutional supercooling during directional solidification of In(0.3)Ga(0.7)As melt

Constitutional supercooling is one of the most important phenomena for crystal growth. There are several theoretical analyses of constitutional supercooling on mixed crystals, but the experimental conditions for the occurrence of constitutional supercooling have not been identified. The constitutional supercooling behavior during directional solidification of a In(0.3)Ga(0.7)As melt was investigated by evaluating concentration distribution of solidified samples. The results showed that the limit of sample traveling rate for constitutional supercooling was between 0.9 mm/h and 2 mm/h when the Solid/Liquid (S/L) interface had a temperature gradient of about 40 to 45 C/cm. The pattern of concentration distribution in various traveling rates was also discussed.