KTN晶体及其熔体结构的高温拉曼光谱研究

测量并研究了不同温度(室温—1573 K)范围内KTN晶体的拉曼光谱及其熔体的高温拉曼光谱，分析了KTN晶体结构随温度变化的规律及其熔体的结构特征.随着温度的升高，KTN晶体的拉曼光谱谱峰都不同程度地向低波数方向移动，同时存在不同程度的展宽，并伴随强度的减弱.观察并解释了温度353 K附近KTN晶体样品的四方—立方转相现象.研究了KTN晶体拉曼光谱中538cm^-1,585cm^-1,835cm^-1和877cm^-1谱峰及其 关键词： 高温拉曼光谱 熔体 KTN晶体

High temperature Raman spectra and micro-structure of KTN crystal and melt

The high temperature Raman spectra of KTN crystal and melt were studied. The structures of KTN crystal and melt were analyzed. The rule of structure change of KTN crystal with increasing temperature was analyzed. The results show that the peaks of spectra move to the lower wavelength and broaden by different degrees. The intensities of spectra peaks decrease, too. Raman peaks at 538, 585, 835, 868 and 875cm^-1 were analyzed in detail. Phase transition from tetragonal to cubic was observed and explained. In high temperalure KTN melt, the ［Ta/NbO₆］ octahedron entities disappeared. Meanwhile, there were many Ta/Nb O double bonds in the ［Ta/NbO₃］^- entities. It showed that there were ［Ta/NbO₃］^- growth unities in KTN melts.