Growth and Macro-defects Study of Lu_2Si_2O_7:Ce Scintillation Crystal

Cerium-doped lutetium pyrosilicate (LPS:Ce) crystal was grown by using the Czochralski method. A series of problems during growth, such as volatilization of the melt, crack and sandwich inclusions, were discussed. Results show that the components of LPS and SiO2 volatilize during growth, and the latter is dominant. As volatilization of LPS will not lead to components segregation, there is not a negative affection on the growth process. Poly-crystal caused by the lower seeding temperature and the biggish thermal stress in the crystal are the main reasons for crystal crack. Sandwich inclusions phenomenon is mainly related to three factors, the first is the narrow crystallization temperature of LPS:Ce crystal, the second is the constitutional supercooling appearing in the melt, and the third is the poor precision of the temperature-monitoring systems of the growth equipment.