| 摘要 |
PURPOSE: To avoid embedding due to dropping of grown crystal and avoid adverse influence on grown crystal due to occurrence of latent heat due to drastic solidification of melt by giving solidifying cause to the melt and solidifying the melt when grown single crystal is gradually cooled in a state separated from the melt face. CONSTITUTION: β-BaB2 O4 single crystal excellent in crystallinity is obtained in good yield by a pulling-up growing method from the melt having BaB2 O4 composition, especially not using flux. BaCO3 is mixed with B2 O3 in a molar ratio of 1:1 as starting raw materials and the mixture is housed in a platinum crucible 2 and the single crystal is grown using a seed crystal 7. After finishing the growth, the single crystal is pulled up to the position which is about 5mm separate from the liquid level of the melt and cooling of the single crystal is started by rotating the crystal in a state in which grown single crystal 8 is pulled up immediately above the melt 1. At the point of time when melt temperature is lowered to a temperature which is about 100 deg. lower than a temperature at which the growth is finished, a part of the seed crystal 7 is folded and the grown single crystal 8 is dropped, but the melt is already solidified and the single crystal is not embedded therein. |
