PREPARATION OF SINGLE CRYSTAL FROM YTTRIUM ALUMINUM GARNET (Y3AL5O12) OR SOLID SOLUTION THEREOF

摘要

PURPOSE:To obtain single crystals of high purity and uniformity from Y3Al5O12 or solid solution thereof in growing the single crystals thereof, by controlling the temperature gradient around a seed crystal and crystal growing part. CONSTITUTION:In preparing single crystals by the floating zone method, a raw material rod obtained by mixing Y2O3 with Al2O3 in such a molar ratio as to give Y3Al5O12 as an optical material, press molding the reusltant mixture, and sintering the press molded material is used as a rod material. A heat insulating or heating apparatus is provided around a seed crystal and grown crystal part in growing the single crystals, and the temperature is controlled to give a temperature distribution of the seed crystal and the grown crystal part in which the crystal growing interface is convex from the seed crystal to the melting part. According to the method, the aimed inexpensive single crystals of high purity and uniformity are easily obtained from Y3Al5O12 or solid solution thereof.