声光晶体TeO_2的生长及缺陷研究  

Study on Czochralski Growth of TeO_2 Single Crystal and Defects

作　　者：季小红[1] 桑文斌[1] 刘冬华[1] 李冬梅[1] 钱永彪[1] 史伟民[1] 闵嘉华[1] 

机构地区：[1]上海大学嘉定校区电子信息材料系,上海201800

出　　处：《人工晶体学报》2001年第1期93-98,共6页Journal of Synthetic Crystals

摘　　要：本文研究了直拉TeO2 晶体中的主要晶体缺陷形成机理 ,讨论分析了TeO2 单晶生长的工艺参数对晶体缺陷的影响。结果表明 :晶体裂缝主要与温度梯度有关 ,温度梯度大于 2 0～ 2 5℃ /cm及出现界面翻转时 ,易造成晶体的开裂 ,位错密度增加 ;晶体中的包裹体主要为气态包裹体 ,它的形成主要与籽晶的转速和晶体的提拉速度有关 ,转速 15～ 18r/min ,拉速 0 .55mm/h ,固液界面微凹 ,可以减少晶体中的气态包裹体 ;晶体台阶由晶体生长过程中温度和生长速度的起伏引起 ,当台阶间距较宽时 ,易形成包裹体。The formation mechanism of main defects in TeO 2 single crystals grown by Czochralski technique and the effects of growth parameters on defects have been studied in this paper.The results showed that the cracking in TeO 2 single crystal is mainly related to the temperature gradient.To avoid the crystal being cracked and to decrease the dislocation density,the crystal can be grown under temperature gradient of 20 25℃/cm.And the incorporation of gas inclusions into the crystal is due to the pulling rate and the seed rotation rate.The crystal without bubbles can be obtained when a rotation rate of 15 18r/min and a pulling rate of 0.55 mm/h are employed,which can lead a concave solid liquid interface.The reason for growth steps in crystal can be explained by the instability of temperature and growth speed during growth process.

关 键 词：声光晶体 氧化碲晶体 晶体缺陷 工艺参数 单晶生长 直拉法 

分 类 号：O782[理学—晶体学] O77