Microstructure and Dielectric Property of Strontium-Lead Titanate Functionally Graded Ceramics

A series of (Sr, Pb)TiO3 system dielectric ceramics with homogeneous and functionally graded compositions were fabricated by sintering process using chemically-coprecipitated (Sr1-xPbx)TiO3 nano-particles, and their compositional distribution, microstructure and dielectric property were investigated as well. The results indicate that, the ceramics are nearly densified and their grains coarse somewhat (mean size is about 6.3μm) after sintering. There are a small number of sealed pores in the ceramics. In homogeneous ceramics, Sr and Pb distribute evenly, while in graded ceramics Sr and Pb vary gradually. The major phase constituent obviously transforms from cubic paraelectric phase to tetragonal ferroelectric phase after sintering, in which the ferroelectric domains exist. The graded constitution effectively optimizes the dielectric property of (Sr, Pb)TiO3 ceramics; the work temperature zone is broadened and the dielectric-temperature stability is improved obviously.