| 摘要 |
PURPOSE:To obtain a high-quality crystal without forming foreign materials on the crystal surface and preventing the surface oxidation, by using a mixture of inert gas and oxygen having a specific concentration as the atmospheric gas in the growth of the crystal, and cooling the crystal at a specific crystal temperature while substituting the atmospheric gas with an inert gas. CONSTITUTION:A desired crystal is grown by heating and melting the raw material 7 for the crystal growth by the direct heating e.g. with infrared radiation 12. In the above process, a mixture of oxygen gas and an inert gas having a partial pressure ratio of oxygen of <=50% is used as an atmospheric gas. The temperature of the crystal 13 during growth in the growth apparatus 1 is maintained at >=1,000 deg.C, and the grown crystal is cooled by at least partially substituting the atmosphere with an inert gas before or around the completion of the growth or is cooled in a substituted atmosphere to obtain a ferrite. |
