2002 年 29 巻 2 号 p. 4-
Growth of langasite single crystal of 4 inch in diameter along Y54 direction by CZ method was investigated. The structure of a hot zone, pulling rate and rotation rate were optimized, and some crystals without a macro defect were obtained. The homogeneity of the crystals was evaluated. The distribution of sound velocity between lots is about 120 ppm in standard deviation.