Process for preparing yttrium oxyfluoride, stabilized yttrium oxyfluoride raw material powder and stabilized yttrium oxyfluoride

摘要

The yttrium oxyfluoride of the present invention is represented by YOF and is stabilized with a fluoride represented by CaF ₂ . The number of moles of Ca is preferably 8 mol or more and 40 mol or less with respect to 100 moles of yttrium. First calcium fluoride powder comprises a mixed powder, or, expressed in CaF ₂ to the raw material powder of the present invention, including oxy-fluoride, yttrium powder, expressed as calcium fluoride powder and, YOF, it expressed as CaF ₂ and, YF ₃ Yttrium powder represented by Y ₂ O ₃ , and a second mixed powder containing yttrium oxide powder represented by Y ₂ O ₃ . The production method of the present invention is a method of firing a formed body of the first or second mixed powder under predetermined conditions.