烧结温度对锆钛酸铅-铌镁酸铅压电陶瓷结构的影响

采用铌铁矿预产物合成法在不同烧结温度下制备组成在准同型相界附近的锆钛酸铅-铌镁酸铅压电陶瓷。采用X射线衍射、拉曼光谱、扫描电镜以及介电温谱对制备陶瓷样品进行表征分析和性能测试。结果表明:所有陶瓷样品的相组成均为纯钙钛矿相;随着烧结温度的升高,陶瓷的相结构由菱方-四方两相共存转变为单一菱方相。对陶瓷断口的观察表明:随着烧结温度的升高,晶粒逐渐长大,陶瓷逐渐致密;陶瓷的平均晶粒尺寸约为3~4μm。制备的压电陶瓷在1 200℃烧结的试样峰值相对介电常数高达19 520,居里温度为310℃。

Influences of Sintering Temperature on Structures of Lead Magnesium Niobate-Lead Zirconate Titanate Piezoelectric Ceramics

Lead magnesium niobate-lead zirconate titanate piezoelectric ceramics near the morphotropic phase boundary were prepared by the columbite precursor method at different sintering temperature. The phase composition, structure and properties for all ceramics were investigated by X-ray diffraction, Raman spectra analysis, scanning electron microscopy and the temperature dependence of the relative dielectric permittivity. The results showed that the pure perovskite phase was obtained for all the specimens. The phase transition from tetragonal phase and rhombohedral phase coexisted to pure rhombohedral phase with raising the sintering temperature. The fracture face for the ceramics showed that the grain size and density increased with raising the sintering temperature. The average grain size of ceramics was about 3~4 μm. The temperature dependence of the relative dielectric permittivity of ceramic samples showed that the value of maximum dielectric constant reached about 19 520 for the ceramics sintered at 1 200 ℃, and the Curie temperature was about 310 ℃.