Dielectric behavior of Ba-doped CaCu3Ti4O12 ceramics prepared from citrate-nitrate combustion derived powders

Ca(Cu3-x Ba (x) )Ti4O12 ceramics (x = 0, 0.05, 0.1, and 0.2) were prepared by the citrate-nitrate combustion derived powders. Effects of Ba2+ substitution on the microstructure and dielectric properties of CaCu3Ti4O12 ceramics were investigated. The mean grain size decreased with increasing Ba2+ concentration, which was ascribed to the ability of Ba2+ doping to inhibit grain boundary mobility. Substitution of Ba2+ into CCTO improved dielectric stability with frequency and maintained a high dielectric constant and low dielectric loss over a broad range in temperature and frequency compared to the undoped sample.