以醋酸钡、醋酸铅和钛酸丁酯为原料,醋酸和甲醇为溶剂,采用溶胶-凝胶工艺制备了不同晶粒大小的掺铅(5 mol%)钛酸钡(BPT)纳米晶.用XRD、TEM和Raman研究了BPT样品的晶粒大小、结构及其相变特性.结果表明BPT纳米晶最低晶化温度为550℃,高于650℃热处理的纳米晶BPT在常温下为四方相.随着晶粒尺寸的减小,BPT纳米晶由四方相向立方相过渡.

Nanocrystalline (Ba_1-xPb_xTiO₃ (x=0.05) powders were prepared by a solgel process and controlling the crystal size through the heattreat temperature. The particlesize dependence of the ferroelectric phase transition in nanocrystalline BPT has been investigated by xray diffraction (XRD) and Raman scattering. The results showed that at room temperature, the tetragonality ratio (c/a) decreased monotonically and became more diffusive in nature with decreasing particle size, the phase transformation from tetragonal to pseudocubic symmetry occurs at below 20 nm.