Dielectric, structural and spectroscopic properties of mg-doped CaCu3ti4o12 ceramics by the solid-state reaction method

Abstract

Since the discovery of the gigantic dielectric constant in the CCTO supercapacitor in 2000, development of its practical application for energy storage has been of great interest. In this study, the CaCu3Ti4O12 (CCTO) and Mg doped CCTO ceramic samples (Ca1- xMgxCu3Ti4O12) were synthesized by the traditional solid-state reaction method using CaC03, CuO, MgO, and TiO2. This was achieved in a shorter time compared to conventional ceramic methods. The precursors were calcined at 950 C in air for 12 h to obtain nanocrystalline powders of CCTO and Mg doped CCTO samples and then the samples were sintered at 10000C in air for 12h. The sintered CCTO and Mg doped CCTO samples were characterized by XRD, FTIR, and Raman spectroscopy. The XRD results indicate that all the sintered samples have a typical perovskite CaCu3Ti4O12 structure and small amounts of CuO and Rutile. From the FTIR spectra, the modes observed at 606, 525 and 463 cm-1 were assigned to vibration modes of Ca–O, Cu–O and Ti–O–Ti, respectively. The dielectric constant of x=0 at 1 kHz is about 12734 increasing to 18381 with higher Mg2+ (x= 0.4) content. However, the dielectric constant for the x=0.08 sample shows different behavior leading to a decrease in the dielectric constant. The dielectric loss of CCTO samples can be reduced with the addition of Mg dopant