Cu2O addition and sintering temperature dependence of structural, microstructural and dielectric properties of CaCu3Ti4O12 ceramics

Abstract

This study is aimed in the replacement of commonly used (CuO) by Cu2O in the synthesis of perovskite CaCu3Ti4O12 (CCTO) phase by the solid-state reaction method. The XRD analysis of powder calcined at 1100 °C and ceramics sintered at different temperatures show that the CCTO phase was well crystallized with the presence of small quantities of additional phases. The SEM/EDS analysis of prepared pellets show that the formation of Cu2O/CuO phase occurs above 950 °C, resulting in enhanced densification at 1050 °C (>96%). However, it is found that the Cu2O-based CCTO begins to degrade around 1090 °C. The densification after sintering at 1050 °C reaches 96%, meanwhile dielectric constant and loss tangent values are optimum in the low frequency range (<103 Hz); i.e. 13378 and 0.177, respectively. This favors the use of Cu2O instead of CuO in CCTO ceramics for applications at low frequencies.