Synthesis and dielectric anomalies of CdCu3Ti4O12 ceramics

CdCu3Ti4O12 ceramics were successfully synthetized by the conventional solid-state reaction method. The influences of sintering parameters on phase structure, microstructure and dielectric properties were investigated systematically. CdCu3Ti4O12 ceramics sintered at 1020 °C for 15 h exhibited high temperature stability and outstanding dielectric properties, evidenced by the △CT/C25 °C ranges from −14.8% to 12.1% measured from −55 to 125 °C at 1 kHz, and the giant dielectric constant ε′=2.4×104 as well as dielectric loss tanδ=0.072. Four dielectric anomalies were evidenced in dielectric temperature spectra and the related physical mechanisms were discussed in detail. The oxygen vacancies play an important role in dielectric anomalies in the high temperature range.