中文摘要：

PZT基多元系压电陶瓷在三方相含量与四方相含量相等的准同型相界处（MPB）具有极为优异的压电性能。文章采用拉曼散射方法研究了0.5PZN-0.5PZT陶瓷体系中三方-四方相共存与弥散相变现象。研究发现,与纯PZT相比,0.5PZN-0.5PZT体系拉曼谱呈明显宽化特征,表明体系弛豫性较强,依据介温谱计算出弥散因子γ高达1.71。通过对拉曼谱峰进行Gauss函数拟合,定量计算三方相R1模式与四方相E（3TO）和A1（3TO）模式相对强度,以及四方相E（4LO）和A1（3LO）模式与三方相Rh模式相对强度,结果表明0.5PZN-0.5PZT体系三方相与四方相含量相等,组成位于准同型相界,该结果得到XRD相分析验证。电学测量表明0.5PZN-0.5PZT陶瓷压电性能优异：kp=0.66,d33=425 pC/N,适宜作为压电致动器材料使用。

英文摘要：

PZT based multi-system has shown super piezoelectric properties when the composition was located at morphotropic phase boundary （MPB）, which divided the regions into rhombohedral and tetragonal structures equally. In the present paper, the diffuse phase transition and phase coexistence of rhombohedral and tetragonal phases of 0. 5PZN-0. 5PZT ceramics were investigated by Raman scattering spectroscopy in detail. The results revealed that compared with pure PZT, the width of Raman bands of 0. 5PZN-0. 5PZT was quite broad, indicating that the system has strong relaxor feature. According to the temperature dependence of dielectric permittivity, the indicator of degree of diffuseness, γ, was calculated and the values were as high as 1.71. Through the separation by Gauss fitting of the Rarnan bands, the intensities of different Raman vibration modes, such as the tetragonal E（3TO）, A1 （3TO）, E（4LO） and A1 （3LO） modes, as well as the rhombohedral R1 and Ra modes, were determined. The results indicated that for 0. 5PZN-0. 5PZT system, the fraction of rhombohedral phase was equal to the tetragonal phase, which has also been affirmed by XRD results and suggested that the system was close to the MPB. Excellentpiezoelectric properties, such as kp （0. 66） and d33 （425 pC/N）, were found in 0. 5PZN-0. 5PZT system, showing a great promise of this system as practical materials for piezoelectric actuators.