Dielectric studies of CCTO-based nanocomposite ceramic synthesized by a solid state route

Abstract

Abstract In the present work, the nanocomposite 0.9CaCu3Ti4O12–0.1BaTiO3 (CC-BT) is synthesized by a solid-state reaction method by sintering at 950°C for 12 h. X-ray diffraction analysis confirms the presence of both BaTiO3 and CaCu3–Ti4O12 phases in the composite ceramic. Transmission electron microscopy analysis of the composite demonstrates the formation of nanoparticles with an average particle size of 40 ± 5 nm. The surface morphology of the composite sintered at 950°C for 12 h obtained by scanning electron microscopy analysis indicates the evolution of large and small grains with a bimodol distribution. The average and root mean square roughness were found to be 1.41 nm and 2.24 nm respectively by atomic force microscopy studies. The dielectric constant of CC-BT ceramic was determined to be 6231 at 100 Hz and 500 K. The presence of the semiconducting grains and the insulating grain boundaries in the composite supports the internal barrier layer capacitance mechanism operative in CC-BT nanocomposite.