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)(3)Ti4O12 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. (C) 2008 Elsevier Ltd. All rights reserved.