CZOCHRALSKI METHOD;
AL2O3 SINGLE CRYSTALS;
TI DOPED AL2O3 SINGLE CRYSTALS;
BUBBLE;
EFFECTIVE SEGREGATION COEFFICIENT;
CONVECTION;
CONSTITUTIONAL SUPERCOOLING;
D O I:
暂无
中图分类号:
TQ174 [陶瓷工业];
TB3 [工程材料学];
学科分类号:
0805 ;
080502 ;
摘要:
The effects of growth parameters on bubble formation in Al2O3 crystals in the Czochralski method were investigated. Pure Al2O3 single crystals were bubble free both under non-reducing and reducing atmospheres. Ti doped Al2O3 single crystals grown under a H-2-containing atmosphere were bubble free and those grown under non-reducing atmospheres contained many bubbles. The effective segregation coeffcient of Ti ions was estimated to be greatly reduced under non-reducing atmospheres. Convection of the melt was remarkably enhanced under a H-2-containing atmosphere. The conditions for the bubble formation is concluded to be similar to that of constitutional supercooling.