J Mater Sci Technol ›› 2010, Vol. 26 ›› Issue (8): 682-686.

• High Temperature Structural Materials • Previous Articles     Next Articles

Enhanced Dielectric Response in Mg-doped CaCu3Ti4O12 Ceramics

Wang Li1), Shenyu Qiu1,2), Nan Chen1), Guoping Du1)   

  1. 1) School of Materials Science and Engineering, Nanchang University, Nanchang 330031, China
    2) Department of Science, Nanchang Institute of Technology, Nanchang 330099, China
  • Received:2009-10-30 Revised:2009-12-07 Online:2010-08-28 Published:2010-08-23
  • Contact: Guoping Du
  • Supported by:

    the National Natural Science Foundation of China (Grant Nos. 60661001, 60844008), the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT0730), and the Program for Innovative Research Team of Nanchang University

Abstract:

CaCu3Ti4O12 ceramics substituted by Mg for Ca were prepared by the solid state reaction method. The crystal structures, microstructures, and dielectric properties of the Ca1-xMgxCu3Ti4O12 ceramics were investigated. At lower doping concentrations, the substitution of Mg for Ca caused a decreased lattice constant, while at higher doping concentrations, some of the Mg dopants started to replace Ti and resulted in an increased lattice constant, and some could also replace Cu due to the similar ion radius between Mg and Cu ions. Mg doping was found to promote the grain growth of Ca1-xMgxCu3Ti4O12 ceramics during sintering. Grain boundary resistance of the Ca1-xMgxCu3Ti4O12 ceramics was found to be increased by Mg doping. Enhanced dielectric properties was observed in the Ca1-xMgxCu3Ti4O12 ceramics with x=0.05 for the frequency range from 1 kHz to 20 kHz. For other doping concentrations, the dielectric losses of Ca1-xMgxCu3Ti4O12 ceramics were generally lowered.

Key words: Electroceramics, Dielectric properties, CaCu3Ti4O12, Sintering