Microstructure evolution and dielectric properties of Ce doped SrBi4Ti4O15 ceramics synthesized via glycine nitrate process
Ce doped strontium bismuth titanate (SrBi4Ti4O15, SBT) powders were prepared by glycine nitrate process at 400 500degC and the ceramics were sintered at 980degC. The phase composition, morphology and electric properties were investigated. It was found that the calcined powders consist of a single phase SBT and the calcination temperature is lower than that for the conventional solid state method. The morphology of Cedoped SBT is flake like and the layer size decreases with Ce addition from 12 to 2mm confirming that the addition of Ce3+ inhibits grain growth. The Curie temperature of Ce doped SBT increased for about 20degC compared to the pure SBT. The tan d was ~0.005 at 35degC and even below 0.05 up to 400degC. The temperature coefficient of dielectric constant was ~0.012 and the rate of frequency change was 0.01 0.04, which indicated the high stability of dielectric properties of the Ce doped SBT. Impedance analysis revealed that the conduction mechanism of the Ce doped SrBi4Ti4O15 ceramics is mainly grain conduction.