Dielectric Relaxation and Microstructures of SnO2 Doped CaCu3Ti4O12 Electroceramics Prepared Via Vibro-milling Method

Abstract

High dielectric constant CaCu3Ti4O12 (CCTO) is a compound with a high dielectric constant, but it has a high loss tangent at room temperature. This research aims to study on the dielectric properties and loss tangent of SnO2 doped CaCu3Ti4O12 (CCTO) ceramics were investigated. The ceramic samples of SnO2 doping CCTO were prepared by a solid-state reaction method. The characterization of the samples was carried out using scanning electron microscopy (SEM) and x-ray diffraction (XRD). The conventional solid-state reaction was employed. The metal oxide powders were mixed using a vibratory milling for 6 hour and sintered at 1000°C for 4 hour. The phase formation of the calcined powders and sintered ceramics was examined by X-ray diffraction technique (XRD). Microstructure was examined by scanning electron microscopy (SEM). SnO2 doping produced a notable decrease in grain size. Average values of grain size, as measured by the linear intercept method. The dielectric measurements at room temperature to 130°C, in the frequency range 100 Hz– 500 kHz. The XRD result a CCTO structure does not changes on Sn doped samples. The results show the loss tangent at room temperature and at 100 kHz decreased from 0.14 for the 0 mol% Sn doped CCTO sample to 0.04 for the 2.0 mol% Sn doped sample while at 500 kHz, it was decreased from 0.2 for the undoped CCTO sample to 0.04 for the 2.0 mol% Sn doped sample. However, the lowest loss tangent was 0.02 at 500 kHz and at 65°C and show a stable loss tangent in temperature range 25 – 130°C.