MELT MIXING OF THE 0.3IN 0.7GASB/0.3SB SOLID COMBINATION BY DIFFUSIONUNDER MICROGRAVITY/

In order to investigate the effects of diffusion and convection on the melt mixing of semiconductors, experiments under microgravity in spac e and l-g on earth were conducted. Sandwich combinations of In/GaSb/Sb solids closed in a BN cylinder were heated up to 733 degrees C in spa ce and 744 degrees C on earth: and they were then cooled rapidly. In b oth samples, many needle crystals were distributed in the whole area. It was observed that the melt mixing in space was controlled by diffus ion which was represented with an error function, and the diffusion co efficient of indium uas given by a value of 2.4 x 10(-4) cm(2)/s. In t he earth sample, however, the indium concentration distribution follow ed an exponential curve. This indicated that both factors; diffusion a nd thermal convection; have contributed to the mixing of semiconductor melts.