Microstructures and dielectric properties of CaCu3Ti4O12 ceramics via combustion method
Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong
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Revised: 29 September 2011
Accepted: 7 October 2011
Published online: 2 December 2011
CaCu3Ti4O12 (CCTO) powder was synthesized by the combustion method. The effect of sintering temperature was studied on dielectric properties of the prepared ceramic samples. They have the dielectric constant of ~31 000 and 80 000 for the grain size of 0.3 and 30–100 μm. It is unusual for CCTO with a grain size of 0.3 μm to have a dielectric constant of ~31 000. Their giant dielectric constant could be explained by a two-step internal-barrier-layer-capacitor model, associated with grain boundaries and domain boundaries. The existence of domain boundaries helped to explain the contradiction of the dielectric mechanisms between polycrystalline and single-crystal CCTO.
© EDP Sciences, 2011