Microgravity experiment to understand the effect of convection on PVT crystal growth

We have carried out very extensive theoretical and experimental studies on the physical vapour transport (PVT) growth of mercurous chloride. A microgravity experiment on the growth of mercurous chloride was designed and performed in the Space Experiment Facility (SEF) transparent furnace that was flown on Spacehab 4 (STS 77). Growth ampoules and cartridges were designed and fabricated to meet the science requirements. Two crystals were grown at the same time in the same furnace in <110> orientation at an speed of 5.5 mm/day and 8 mm/day by physical vapor transport in the microgravity condition to reduce gravity driven convection. The direct observation was made on the interface during the growth of crystals. We observed convex and detached growth for both growth runs. (C) 2003 COSPAR. Published by Elsevier Ltd. All rights reserved.