Influence of sintering conditions on microstructure and electrical properties of CaCu3Ti4O12 (CCTO) ceramics

CaCu3Ti4O12 (CCTO) ceramic was prepared by the solid-state method. The microstructure, dielectric properties, complex impedance and nonlinear I-V characteristic were studied. The results show that increasing the sintering temperature, most grains grow up firstly, and then some diminish, resulting in depravation of the comprehensive properties in varying degrees. While prolonging sintering time promotes grain growth, microstructural densification, and improves the dielectric and nonlinear I-V properties. It should be noted that the CCTO ceramics sintered at 1050 degrees C for 12 h exhibit giant dielectric constant of 10(5) and low dielectric loss <0.1 with weak frequency dependence below 1 MHz, as well as a nonlinear I-V coefficient of 5.27. (C) 2015 Elsevier B.V. All rights reserved.