Zn:Fe:LiNbO_3单晶的坩埚下降法生长及其成分研究  

GROWTH OF LiNbO_3 SINGLE CRYSTALS CO-DOPED Fe AND Zn BY BRIDGMAN TECHNIQUE AND THEIR COMPOSITION

作　　者：夏海平[1] 王金浩[1] 曾宪林[1] 章践立[1] 张约品[1] 徐键[1] 聂秋华[1] 

机构地区：[1]宁波大学光电子功能材料重点实验室,浙江宁波315211

出　　处：《硅酸盐学报》2004年第5期594-598,共5页Journal of The Chinese Ceramic Society

基　　金：浙江省科技厅(011066);宁波市博士科学基金(02J2010112)资助项目。

摘　　要：通过优选合适的化学原料,用坩埚下降法生长出了无宏观缺陷的Zn∶Fe∶LiNbO3(Zn∶Fe∶LN)单晶。生长的工艺参数是:用微凸生长界面生长,生长速度为1～3mm/h,温度梯度为20～30℃/cm。用X射线衍射及DTA对晶体进行了分析;测定了晶体的吸收光谱。结果表明:所有Zn∶Fe∶LN晶体中的Fe2+浓度沿生长方向增加;掺杂3%ZnO(摩尔分数)的Zn∶Fe∶LN单晶中的Fe2+浓度沿生长方向的变化量比掺杂6%ZnO的大。从坩埚下降法的温场特点、晶体的热处理过程、环境气氛,以及ZnO组分对Fe离子的排斥作用解释了产生Fe2+离子浓度变化的原因。Large sized LiNbO3 (LN) single crystals doped with Fe and Zn ions (Zn∶Fe∶LN) were prepared by the Bridgman method at the optimum growth conditions such as proper raw materials, sealed platinum crucibles, growth rate of 1—3 mm/h and convex solid-liquid interface with temperature gradient around 20—30 ℃/cm. The LN crystals obtained were characterized by means of XRD and DTA. The UV/VIS absorption spectra of crystals were measured. The results indicate that the concentration of Fe2+ ions in Zn∶Fe∶LN crystals increases along growth direction, and the Fe2+ ion concentration of Zn∶Fe∶LN crystals doped with 3% ZnO (molar fraction, same below) changes along the growth direction much more than doped with 6% ZnO. The reason for the concentration changes of Fe ions can be interpreted by the suppressing effect of ZnO for the incorporation of a Fe ions, thermal field of furnace, the thermal treatment for the crystals and the growth environment.

关 键 词：锌铁双掺铌酸锂晶体 熔体晶体生长 坩埚下降法 

分 类 号：TB381[一般工业技术—材料科学与工程]