Dielectric properties of CaCu3Ti4O12 ceramics fabricated with high purity nanometric powders

The characteristics of raw material powders, such as the purity and average particle size, have a major impact on the microstructure and properties of the CaCu₃Ti₄O₁₂ ceramics. The properties of CaCu₃Ti₄O₁₂ ceramics fabricated with nano-size powders (~30 nm) are compared with those of the samples with submicron powders (0.1~0.3 μm). It is found that, the samples fabricated with nano-size powders have homogenous microstructure and stable performance, and the dielectric constant is improved by an order of magnitude. It is considered that the relaxation peak with the energy level of 0.38 eV is dominated by impurity defect which mainly originates from raw materials, because this peak disappears in the samples with high purity raw material. This research provides a technical guidance for the application of this material.