四硼酸锂晶体的介电频域谱研究  

Investigation on the Dielectric Spectra of Lithium Tetraborate Crystal

作　　者：熊正烨[1] 徐家跃[2] 李永强[1] 申慧[2] 熊小敏[3] 

机构地区：[1]广东海洋大学理学院,广东湛江524088 [2]上海应用技术学院材料科学与工程学院,上海201418 [3]中山大学物理工程与技术学院,广东广州510275

出　　处：《广东海洋大学学报》2013年第1期89-92,共4页Journal of Guangdong Ocean University

摘　　要：选用优质四硼酸锂单晶加工成小薄片后测量其频域介电谱。在kHz至1 MHz范围内,观察到空间电荷等所引起的损耗峰,但损耗峰形复杂,不能用用德拜弛豫模型描述;从科尔—科尔图的趋势可以判断该晶体中,空间电荷引起的介电常数变化范围约为9.98~10.07。由紫外吸收谱估算出电子谐振频率高于1.67 PHz,根据光频段的介电色散模型,分析了折射率测量的实验结果,可得：晶体中电子极化的直流介电常数约为2.55,偶极取向极化和原子（离子）极化对直流介电常数的贡献约为7.43。The dielectric spectra of lithium tetraborate （LTB） single crystal were measured after the single crystal was cut into some wafers. In the range of 1 KHz to 1MHz, there is a loss peak which can be caused by some space charge, the peak＇s shape is so complex that it cannot be represented with Debye relaxation model; it can be deduced with the Cole-Cole plot of the crystal that the range of dielectric constants is about 9.98-10.07. It can be seen from the UV absorption spectrum that the electronic resonant frequency in LTB crystal is higher than 1.67PHz; based on the dielectric dispersion model of optical frequency, it can be figured out with the refractive index measurement results that the DC dielectric constant of electronic polarization is about 2.55 and the ion polarization＇s contribute to DC dielectric constant is approximately 7.43.

关 键 词：四硼酸锂 介电常数 极化 

分 类 号：O487[理学—固体物理] TQ128[理学—物理]