Mode of Occurrence and Cause of Twinning in Lithium Tetraborate Grown by Czochralski Method

Mode of occurrence and cause of twinning, which are occasionally observed in lithium tetraborate crystals grown pararell to [110], have been investigated. Twinning is related to the crystal symmetry, i.e., 4-fold screw axis along the c-axis. Relashionship between the cause of striations in crystals and the occurence of twinning during growth has also been examined in connection with temperature fluctuations near the interface.