GRAVITATIONAL EFFECTS ON MIXING AND GROWTH-MORPHOLOGY OF AN IN0.5GA0.5SB SYSTEM

A mixing experiment of multicomponents melts was performed using a uni form temperature furnace in the Second International Microgravity Labo ratories (IML-2) mission. Growth morphologies and Ga concentration pro files were analyzed for the samples with the compositional ratio of 0. 5 In-0.5 Ga-1.0 Sb grown under microgravity and on earth. The sample w ith free surface grown under microgravity was nearly spherical in shap e, except some parts with projections. Ga was dispersed homogeneously in the bulk because the mixing was enhanced by Marangoni convection du e to the concentration gradient. On the other hand, the sample grown o n earth was a double cylindrical shape with different diameters, and G a concentration decreased from top to bottom, showing clearly the effe ct of gravity. Many needle crystals were formed in both space and eart h samples due to rapid cooling. The average size of the needle crystal s grown in space was larger than that of the earth sample.