Ca_(0.4)Ba_(0.6)Nb_2O_6晶体的生长和低温拉曼光谱研究  

Growth and Low-temperature Raman Spectra Study of Ca_(0.4)Ba_(0.6)Nb_2O_6 Crystal

作　　者：张娜娜[1] 韩树娟[1] 高文兰[1] 张怀金[1] 王继扬[1] 

机构地区：[1]山东大学晶体材料国家重点实验室,济南250100

出　　处：《人工晶体学报》2011年第5期1093-1096,共4页Journal of Synthetic Crystals

基　　金：国家自然科学基金(50872066);国家自然科学基金重点项目(51032004);国家重点基础研究发展计划(2010CB833103)资助项目

摘　　要：采用提拉发生长了Ca0.4Ba0.6Nb2O6晶体,利用偏振拉曼光谱研究了Ca0.4Ba0.6Nb2O6晶体在低温25～260 K范围内的结构稳定性。实验发现,随温度降低,NbO6六面体的内振动(ν5)模的非对称性增加,由Gauss+Lor Amp拟合得出的相对低频(ν5)模波数和相对高频(ν5)模峰宽在70～100 K时发生突变,表明该晶体在此温度范围内可能存在相变。同时分别讨论了在x(zz)x和x(zy)x不同偏振配置下,外振动模的相对强度比随温度的变化趋势,同样发现其在该温度范围内发生明显异常。最后简单讨论了布居因子对拉曼散射强度和实验结果的影响。The Ca0.4Ba0.6Nb2O6 crystal was grown by Czochralski method.The stability of crystal structure of Ca0.4Ba0.6Nb2O6 at low temperature 25-260 K was investigated by polarized Raman spectrum.The results indicated that as the temperature decreasing,the internal ν5 mode of NbO6 increases more unsymmetric,and the wavenumbers of lower-ν5 mode and the width of higher-ν5 mode obtained from Gauss＋Lor Amp fitting show obvious variation at 70-100 K,which indicates the possibility of a structure transformation.Meanwhile,the temperature dependence of ratios of external modes under x（zz）x and x（zy）x polarizations was discussed,which also show abnornality at this temperature range.At last,the effect of population factor on Raman intensity and the experiment result was simply discussed.

关 键 词：Ca0.4Ba0.6Nb2O6晶体 晶体生长 提拉法 相变 拉曼光谱 

分 类 号：TN304.054[电子电信—物理电子学]