Towards enhanced varistor property and lower dielectric loss of CaCu3Ti4O12 based ceramics

A novel (1 - x)CaCu3Ti4O12-xY2/3Cu3Ti4O12 composite ceramic was developed. Two perovskite-like grains, i.e. CaCu3Ti4O12 grains of 1-2 mu m and Y2/3Cu3Ti4O12 grains of 4-6 mu m, can be both detected in the samples. High Schottcky barrier height and grain boundary resistance were formed via combining these two perovslcite-like phases, which plays the critical role on the varistor and dielectric performance. Greatly enhanced nonlinear coefficient of 9.88 and very low dielectric loss of 0.02 can be achieved in the composite ceramics accompanied with the permittivity of similar to 2000, compared with reported results of 2-6 and 0.05-0.8 for general CaCu3Ti4O12 ceramics. This varistor-capacitor multifunctional characteristic makes it a promising material in the field of over voltage protections of electronic devices. (C) 2015 Elsevier Ltd. All rights reserved.