Effect of microwave sintering time to the microstructure and phase properties of conventional heat treated CaCu3Ti4O12 after calcination

Most of the research regarding CCTO nowadays have been conducted by producing CCTO using conventional solid-state processing technique. However, the production of a single-phase CCTO body obtained by conventional solid-state reaction routes is quite troublesome as the procedure requires calcination and sintering process at a high temperature and long span to get the ideal properties. Hence this study is conducted to study the effect of microwave heat treatment to the as-sintered CaCu3Ti4O12 pellets and to synthesise single phase CaCu3Ti4O12 (CCTO) powder with the help of conventional furnace, microwave processing and formulated microwave susceptor crucible. CaCu3Ti4O12 electroceramic was prepared by a microwave assisted solid-state reaction technique from CaCO3, CuO and TiO2 powders. Processing involved the preparation of raw material, mixing and milling, calcination, pellet forming and sintering processes. Conventional furnace and microwave assisted sintering processes were employed in order to improve phase structures, morphology and dielectric properties of CaCu3Ti4O12 ceramics. It shows that a single-phase CCTO product can be prepared by the post-sintering microwave-assisted combustion reaction using a domestic microwave oven. The research has proven that microwave processing possesses a lower temperature and lower energy to produce a single-phase CCTO compared to the conventional furnace processing which requires a higher temperature and thus a higher energy.