Abstract: A series of (Sr, Pb)TiO₃ system dielectric ceramics with homogeneous and functionally graded compositions were fabricated by sintering process using
chemically-coprecipitated (Sr_1-xPb_x)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.

Key words: strontium-lead titanate, functionally graded materials, microstructure, dielectric property