Enhanced giant dielectric response in Mg-substituted CaCu3Ti4O12 ceramics

Effects of Mg-substitution on the giant dielectric response in CaCu3Ti4O12 ceramics were investigated and discussed. A significantly enhanced giant dielectric response was obtained in Ca(Cu1−xMgx)3Ti4O12 ceramics, and the dielectric constant step increased with increasing Mg-substitution content. The results of X-ray photoelectron analysis confirmed the obvious increase of Ti3+/Ti4+ ratio, and the enhanced giant dielectric response should originate from the corresponding modification of the mixed-valent structure. The present results have great scientific significance in deepening the understanding on the origin of giant dielectric response and modulating the giant dielectric constant step in CaCu3Ti4O12.