Modified Ba3Sm3Ti5Ta5O30 dielectric ceramics

Dielectric ceramics of Ba3Sm3Ti5Ta6O30 were modified by introducing the nonstoichiometric composition Ba3−3xSm3+2xTi5Ta5O30 and the sintering characteristics, microstructures and dielectric properties of Ba3−3xSm3+2xTi5Ta5O30 ceramics were investigated as a function of the composition. Ba3−3xSm3+2xTi5Ta5O30 dense ceramics, sintered at 1400–l430°C, have complex phase constitutions, containing the tungsten–bronze major phase and the pyrochiore secondary phase. With increasing x, the temperature coefficient of dielectric constant (τε) was pronouncedly improved from −l050 to −610 ppm/°C without considerable increase of dielectric loss, but the dielectric constant (ε) decreased considerably.