LiCaAlF_6单晶的非真空坩埚下降法生长  

Growth of LiCaAlF_6 Single Crystal by Vertical Bridgman Method in Nonvacuum Atmosphere

作　　者：方奇术[1] 王苏静[1] 梁哲[1] 周燕飞[2] 武安华[2] 陈红兵[1] 

机构地区：[1]宁波大学宁波市新型功能材料及其制备科学国家重点实验室培育基地,浙江宁波315211 [2]中国科学院上海硅酸盐研究所,上海200050

出　　处：《宁波大学学报（理工版）》2010年第2期66-70,共5页Journal of Ningbo University：Natural Science and Engineering Edition

基　　金：浙江省自然科学基金(Y4090057);宁波市自然科学基金(2009610016)

摘　　要：以高纯氟化物LiF、CaF2和AlF3为初始试剂,按照精确化学计量比1:1:1摩尔比配料,经高温氟化处理合成严格无水的LiCaAlF6多晶料.将该多晶料密封在铂坩埚中,添加少量聚四氟乙烯粉末,可避免氟化物熔体的氧化与挥发,从而在非真空条件下实现LiCaAlF6单晶的坩埚下降法生长.在单晶生长过程中,炉体温度控制于910～930℃,固液界面温度梯度为30℃.cm-1左右,坩埚下降速率为0.5～1.0mm·h-1,成功生长出无色透明的LiCaAlF6单晶.应用XRD、透射光谱,红外光谱进行了LiCaAlF6单晶基本性质的测试表征.结果表明,该单晶在190～1100nm区域内的光透过率达85%以上.The growth process of single crystal LiCaAlF6 by vertical Bridgman method is reported in this paper.Using LiF,CaF2 and AlF3 as the initial agents,the feed material for the crystal growth is prepared according to the molar ratio of LiF：CaF2：AlF3 =1：1：1.The anhydrous LiCaAlF6 polycrystalline material is synthesized by fluoridation process at elevated temperature.By means of sealing the feed material in a platinum crucible,LiCaAlF6 crystal can be grown using the vertical Bridgman method in a nonvacuum atmosphere as the oxidization and volatilization of the melt can thus be avoided.In the Bridgman growth,the furnace temperature is controlled at 910～930℃ and the temperature gradient across the solid-liquid interface is adjusted to approximate 30℃.cm-1.With the crucible lowering rate in the range of 0.5～1.0 mm.h-1,a transparent LiCaAlF6 crystal has been grown successfully in the vertical Bridgman process.The crystal is characterized with XRD,transmission spectrum,IR spectrum.The transmission spectrum indicates a high optical transmittance of more than 85% in a wide wavelength region from ultraviolet to infrared.

关 键 词：LiCaAlF6 氟化处理 单晶生长 坩埚下降法 

分 类 号：O782[理学—晶体学]