Effect of minor phase (CuO) on sinterability, grain size, and dielectric properties of CaCu3Ti4O12 ceramics

Abstract

CaCu3Ti4O12 (CCTO) electro ceramic was prepared by a solid-state reaction technique. The formation of CCTO was confirmed by X-ray diffraction (XRD). Pellets of calcined powder were sintered at different temperatures for two different durations, i.e., 2 and 10 h (h). The morphology and grain size of the samples were observed using scanning electron microscopy (SEM). SEM images showed that the minor phase (CuO) plays an important role in the growth of grain size. It seems that higher sintering temperatures led to change in the oxidation states of Cu and Ti, which increase the volume fraction of the CuO minor phase. Dielectric studies show that the dielectric constant is increasing with increasing sintering temperature, holding time, and presence of the CuO phase. The highest dielectric constant of ~ 41,000 was observed for CCTO samples sintered at 1100 °C for 10 h. The present samples find application in the energy storage devices.