Synthesis and dielectric properties in the 0.65Pb(Mg1/3Ta2/3)O3-0.35PbTiO3 system modified with BaO

The correlation between the sintering temperature, grain size, and dielectric properties of relaxor ceramics in the 0.65Pb1-xBax(Mg1/3Ta2/3)O3-0.35PbTiO3 solid solution series have been investigated. The stability of the perovskite phase was studied as a function of sintering temperature. Sintering studies at different temperatures revealed that the dielectric constant increased with increasing grain size in these ceramics. The dielectric constant at Tc increases with additions of BaO up to 1 mol% and then decreases with further additions of BaO. The pyroelectric and piezoelectric properties of this system were improved by adding a small amount of BaO.