METHOD FOR PRODUCING RAW MATERIAL FOR GROWING SINGLE CRYSTAL, SINGLE CRYSTAL GROWING RAW MATERIAL AND SINGLE CRYSTAL

摘要

PURPOSE: To decrease the weight reduction before and after heat-treatment close to the theoretical value and obtain a raw material for growing a single crystal having elemental ratios same as those of the raw material by heat- treating a charging mixed raw material composed mainly of K₂CO₃, Li₂CO₃ and Nb₂O₅ under specific condition. ;CONSTITUTION: A charging mixed raw material is produced by using K₂CO₃, Li₂CO₃ and Nb₂O₅ as main components and mixing the components at ratios to get elemental ratios K:Li:Nb of preferably 33±0.1:23±0.1:44±0.1. The charging mixed raw material is heated to ≥800°C at a heating rate of preferably 75-200°C/hr and maintained at ≥800°C to perform the heat-treatment. The baking temperature is preferably 800-1000°C, especially 900-960°C and the baking time is about 10-30hr. The elemental ratios of the obtained single crystal growing raw material are K:Li:Nb=33±0.2:23±0.7:44±0.5 or thereabout. A single crystal growing raw material exhibiting SHG activity can be produced because the composition of elements in the charging raw material is maintained in the growing raw material.;COPYRIGHT: (C)1996,JPO