Very high performance dielectric and non-Ohmics properties of CaCu3Ti4.2O12 ceramics for X8R capacitors
- Resource Type
- ACADEMIC JOURNAL
- In Ceramics International 1 August 2018 44(11):13267-13277
CaCu3Ti4O12 (CCTO) and CaCu3Ti4.2O12 (TiO2) precursor powders were prepared by the polymer pyrolysis solution method. Effect of sintering time/temperature on microstructural, dielectric and non-linear properties of CCTO and TiO2 ceramic samples obtained by sintering all precursor powders at various sintering conditions were investigated. Interestingly, very low tanδ ∼ 0.008 and high ε′ ∼ 7221 with temperature coefficients Δε' < ± 15% in a wide temperature range of − 60 to 180 °C were achieved in the TiO2 ceramic sample sintered at 1025 °C for 12 h (TiO2-2 sample). This suggested the potential use of TiO2-2 sample for EIA X5R, X7R and X8R capacitors. Moreover, sintering could enhance the non-linear characteristics of all ceramic samples with a non-linear coefficient (α) of ~ 29.04 and the maximum breakdown field (Eb) of ~ 12,221 V/cm−1 in TiO2-2 sample. Enhancement of ε′ due to the sintering was suggested to originate from the promotion of oxygen vacancies and the increase of grain size.