The Growth of Al2O3 Single Crystals by the Czochralski Method

Shoji MORITA, Hideyuki SEKIWA, Hiroaki TOSHIMA, Yasuto MIYAZAWA
1993 Journal of the Ceramic Society of Japan  
The effects of growth parameters on bubble formation in Al2O3 crystals in the Czochralski method were inves tigated. Pure Al2O3 single crystals were bubble free both under non-reducing and reducing atmospheres. Ti doped Al2O3 single crystals grown under a H2-contain ing atmosphere were bubble free and those grown un der non-reducing atmospheres contained many bub bles. The effective segregation coefficient of Ti ions was estimated to be greatly reduced under non-reduc ing atmospheres.
more » ... of the melt was remarka bly enhanced under a H2-containing atmosphere. The conditions for the bubble formation is concluded to be similar to that of constitutional supercooling.
doi:10.2109/jcersj.101.108 fatcat:sa2nvin7bzg3rjy4kutldlozpq