钨酸铅晶体的低温红外反射谱  

LOW-TEMPERATURE INFRARED REFLECTION SPECTRA OF LEAD TUNGSTATE CRYSTAL

作　　者：孙桂芳[1] 阮树仁[1] 牟娟[1] 钱霞[1] 盛淑芳[1] 

机构地区：[1]聊城大学物理科学与信息工程学院,山东聊城252059

出　　处：《低温物理学报》2013年第4期288-291,共4页Low Temperature Physical Letters

摘　　要：分别在77K、100K、200K和300K温度下测量了钨酸铅(PbWO4,PWO)晶体的红外反射谱,观察到8个反射峰;实验表明PWO晶体在低温77～300K范围内结构稳定.利用Kramers-Kronig(K-K)关系对样品的红外反射谱进行数据处理,获得了不同温度下各振动模的横光学(TO)声子频率ωTO,从而得到了PWO晶体各振动模的温度变化特性,研究表明:Pb2+离子的平动模频率随温度降低发生蓝移,主要是晶格的热膨胀影响;WO42-离子团的振动模频率随温度降低发生红移,主要是非简谐耦合作用影响.The infrared reflection spectra of the Lead tungstate （PbWO4, PWO） crystal were measured at 77K, 100K, 200K and 300K. The measurement results show that the infrared reflection spectra of the PWO crystal have eight reflection peaks. The crystal structure of PWO crystal was stable at 77-300K. Using the Kramers-Kronig （K-K） relation, the data of infrared reflection spectra were processed. The transverse optical （TO） phonon frequency ωπο were obtained at different temperature. The temperature dependence of the lattice vibration mode was ob- tained. The results show that the frequencies of Pb^2＋ vibration mode changes toward higher wave numbers with the decrease of temperature, which are attributed to the thermal expansion. The frequencies of WO4^2- vibration mode changes toward lower wave numbers with the decrease of temperature, which are attributed to the an_harmonic coupling of the phonos.

关 键 词：低温红外反射谱 钨酸铅晶体 光学声子频率 

分 类 号：O734[理学—晶体学]