Hydrothermal crystal growth - recent results.

We review recent literature results on the physical chemistry of hydrothermal solutions and their relevance to synthesis and crystal growth. Included are dielectric constant, thermal expansion and viscosity measurements on near and supercritical water. The author's p-v-T measurements in the hydrothermal system used to grow commercial quartz are described and these results are used to discuss convective crystal growth. Novel hydrothermal equipment designs from the Soviet Union are discussed and our recent new techniques for the "low" temperature growth of potassium titanyl phosphate (KTP) crystals for non-linear optical investigations are reviewed. This review is an invited paper in conjunction with the International Conference on Crystal Growth, York, England, July 1986.