| 摘要 |
PURPOSE:To prepare easily a large amount of gamma type crystal having improved crystallizability, by putting a seed crystal on a melt of a compound oxide of the bismuth oxide type shown by a specific formula through a thermally conductive bar crystal holder, cooling the holder. CONSTITUTION:The melt 2 of a compound oxide shown by the formula BixMOn (M is at least one of Ge, Si, etc., x is 10-14, n is number of oxygen atom determined by M and x) is put in the heat-resistant container 11. The gamma type crystal 4 of the same compound oxide as that of the melt 2 as a seed crystal is fixed to the end 31 of the bar crystal holder 3 consisting of a thermally conductive material such as platinum, brought into contact with the melt 2 and fixed. The whole melt 2 is gradually cooled by cooling the other end 32 of the holder 3. Consequently, the gamma type crystal 5 is grown gradually from a part where the melt 2 comes into contact with the seed crystal 4 toward its periphery, and finally the whole melt 2 is converted into the gamma type crystal. The gradual cooling is carried out at a cooling speed of <= about 20 deg.C/min. |
