| 摘要 |
PURPOSE:To prevent the contamination of iridium used as a crucible and manufacture a large-sized single crystal of high optical completeness in manufacturing chrysoberyl single crystal, by using a mixed gas of an insert gas and oxygen as an atmosphere of a growth furnace. CONSTITUTION:A single crystal is grown from a raw material melt consisting of aluminum oxide, beryllium oxide and an impurity, e.g. chromic oxide or ferric oxide if desired added thereto, e.g. by the Czochralski method. In the process, an inert gas containing about 1-5vol% air is used as a gas to be itroduced into the growth furnace. |
