摘要 |
In order to provide a fluoride refining method and a fluoride crystal manufacturing method that have great general-purpose properties and can reduce the manufacturing cost and to provide at a low cost a fluoride crystal, an optical part and an aligner the transmission characteristics of which are hardly degraded even when repeatedly irradiated with a high-output light of a short wavelength for a long term, there is provided a method of refining a fluoride comprising the heating step of heating a solid scavenger-added fluoride raw material to melt the raw material and the cooling step of cooling the molten fluoride material to solidify the melt, wherein the environment of a chamber housing the fluoride raw material is changed to such an environment that a gas in the chamber is discharged to the outside of the chamber more easily than the environment before the change, during the heating step. <IMAGE> |