Bi_（12）SiO_（20）晶体核芯的形成和消除  

FORMATION AND ELIMINATION OF CORES IN Bi_(12)SiO_(20) CRYSTALS

作　　者：徐学武[1] 廖晶莹[1] 沈炳孚[1] 邵培发[1] 陈显求[1] 何崇藩[1] 

机构地区：[1]中国科学院上海硅酸盐研究所

出　　处：《硅酸盐学报》1994年第6期579-585,共7页Journal of The Chinese Ceramic Society

摘　　要：对于沿〈００１〉、〈１１０〉、〈１１１〉、和〈１１２〉４种取向提拉法生长的直径为３５ｍｍ的ＢＳＯ晶体进行了剖析。用阴影法和光学显微镜观察等方法揭示了ＢＳＯ晶体中深色核芯与生长取向、界面形状及小面生长之间的关系。讨论了核芯形成机制和消除方法。指出通过选择适当的转速，使晶体以平的或凹的界面生长，可消除〈００１〉和〈１１０〉取向生长的ＢＳＯ晶体中的核芯：选择〈１１１〉和〈１１２〉取向生长则能有效地避免深色小面核芯的形成。此外还讨论了生长条纹、组分过冷、应力和位错等缺陷问题。The BSO crystals,35 mm in diameter,pulled along 〈001〉,〈110〉,〈111〉and〈112〉axes were dissected.The relationships among the darkened cores in the BSO crystals,growth direction,interface shape and growth of facets were revealed by methods of shadowgraph and microscopy.The mechanism of core formation and methods of core elimination were discussed.It is shown that the cores in the BSO crystals grown along〈001〉and〈110〉axes can be eliminated by selecting a proper rotation rate which makes the interface shape flat or concave,and that the darkened facet-cores can be effectively avoided by choosing〈111〉and〈112〉 growth direetions. The defects such as growth striation constitutional supercooling,stress and dislocation are also dis-cussed in the paper.

关 键 词：硅酸铋 光折变晶体 深色核芯 界面形状 小面 缺陷 

分 类 号：O614.532[理学—无机化学]