Improved dielectric and non-ohmic properties of Ca2Cu2Ti4O12 ceramics prepared by a polymer pyrolysis method

Non-ohmic and dielectric properties of Ca2Cu2Ti4O12 (CaCu3Ti4O12/CaTiO3 composite) ceramics prepared by a polymer pyrolysis method (PP-ceramic samples) are investigated. The PP-ceramics show a highly dense structure and improved non-ohmic and dielectric properties compared to the ceramics obtained by a solid state reaction method (SSR-ceramic samples). ɛ′ (tan δ) of the PP-ceramic samples is found to be higher (lower) than that of the SSR-ceramic samples. Interestingly, the PP-ceramic sintered at 1050 °C for 10 h exhibits the high ɛ′ of 2530 with weak frequency dependence below 1 MHz, the low tan δ less than 0.05 in the frequency range of 160 Hz–177 kHz, and the little temperature coefficient, i.e., |Δɛ′| ≤ 15 % in the temperature range from −55 to 85 °C. These results indicate that the CaCu3Ti4O12/CaTiO3 composite system prepared by PP method is a promising high-ɛ′ material for practical capacitor application.

Non-ohmic characteristics (J vs. E) of CCTO/CTO ceramic samples.Figure optionsDownload as PowerPoint slideHighlights
► The CaCu3Ti4O12/CaTiO3 composite ceramics prepared by a polymer pyrolysis method show a highly dense structure and improved non-ohmic and dielectric properties compared to the ceramics obtained by the conventional solid state reaction method.
► ɛ′ (tan δ) of the CaCu3Ti4O12/CaTiO3 ceramics prepared by a polymer pyrolysis method is found to be higher (lower) than that of the ceramics obtained by the conventional solid state reaction method.
► The CaCu3Ti4O12/CaTiO3 composite ceramics prepared by a polymer pyrolysis method are desirable for capacitor application with X5R standard-capacitor.