Writers: Anderson A. Felix and Vinícius D.N. Bezzon and Marcelo O. Orlandi and Damjan Vengust and Matjaž Spreitzer and Elson Longo and Danilo Suvorov and José A. Varela
Keywords: CaCu3Ti4O12; Oxygen partial pressure; Phase stability; Non-stoichiometry; Grain growth
Abstract: Phase stability and microstructure evolution of polycrystalline CaCu3Ti4O12 (CCTO) ceramics were studied by controlling the partial pressure of (from a poor to an oxygen rich atmosphere) during the sintering process at high temperatures. The samples were analyzed by X-ray powder diffraction, scanning electron microscopy and X-ray energy dispersive spectroscopy. Our results show that the oxygen partial pressure during the sintering process is an important parameter that controls the phase stability, non-stoichiometry, and decomposition process of the \{CCTO\} phase as well as the densification and grain growth mechanisms on these polycrystalline ceramics. These results provided us further insight into the important role of copper reduction and copper/oxygen diffusion on the crystalline structure and morphological characteristics of polycrystalline \{CCTO\} ceramics.
