准同型相界附近PLZT铁电陶瓷相变的原位Raman谱观测  

PHASE TRANSITIONS NEAR MORPHOTROPIC PHASE BOUNDARY IN PLZT CERAMICS OBSERVED BY IN SITU RAMAN SPECTROSCOPY

作　　者：刘怡萱[1] 程璇[2] 张颖[1] 

机构地区：[1]厦门大学材料学院材料科学与工程系,厦门361005 [2]厦门大学材料学院材料科学与工程系固体表面物理化学国家重点实验室,厦门361005

出　　处：《金属学报》2008年第1期29-33,共5页Acta Metallurgica Sinica

基　　金：国家自然基金10472098~~

摘　　要：对Zr与Ti的原子比约为52/48,掺杂了少量La、Mn和Nb的PLZT铁电陶瓷进行了不同温度下的原位Raman谱观测,对所获得的谱图进行温度分布修正,再利用阻尼-谐振-振荡器模型的光谱响应函数及Gauss分布函数对所得结果进行分峰拟合,得到了各Raman峰的波数和峰强随温度的变化规律.结果表明,准同型相界附近的PLZT铁电陶瓷在47—600℃升温过程中,于240和360℃分别发生两次相变,表明样品中可能存在混合相;通过比较未极化和极化样品的Raman谱峰的变化结果,分析了预极化处理对相变的影响.In situ Raman spectra of PLZT ceramics （atomic ratio Zr/Ti≈52/48, doped with small amount of La, Mn and Nb） were measured at different temperatures and modified by the Bose population factor, and curve-fitted by the damped-harmonic-oscillator model and Gauss distribution function. Accordingly, the variations of Raman shifts and intensities of the modes with temperatures were obtained. It is confirmed that two types of phase transitions near morphotropic phase boundary （MPB） occurred at 240 and 360 ℃, respectively, when the temperatures increased from 47 to 600 ℃, indicating possible presence of mixed phases in PLZT ceramics. The effects of pre-polarization on phase transition are briefly discussed based on the unpoled powders and poled bulk specimens. a comparison of the changes in Raman spectra of the unpoled powders and poled bulk specimens.

关 键 词：准同型相界 铁电陶瓷 相变 原位 RAMAN谱 

分 类 号：TB321[一般工业技术—材料科学与工程]