CRYSTAL-GROWTH AND MATERIALS PROCESSING ABOVE 1000-G

The principal phenomena observed to date during kilogravity crystallization experiments have been rapid sedimentation of precipitates and bubbles and differential molecular sedimentation to form compositional gradients. These experiments indicate that kilogravity fields can be used as a driving force for the rapid growth of inclusion-free crystals, even in systems where growth by conventional techniques is infeasible. Therefore the growth of crystals for high-power optics may become a major application of kilogravity processing. Other potential materials-processing applications include the elimination of microvoids from slip castings, the concentration of sol-gels, and the preparation of materials and precursors with compositional gradients. Although kilogravity experiments involving high temperatures or optical monitoring present serious problems, the necessary apparatus is available or can be developed.