Enhanced breakdown properties and dielectric loss of CaCu3Ti4O12 ceramics via SrO minor addition

Abstract

In this study, CaCu3Ti4O12 (CCTO) ceramics with minor addition of SrO were fabricated by using a sol-gel method, aiming to simultaneously improve the breakdown field strength (Eb) and reduce the dielectric loss (tanδ). The addition of SrO induced precipitation of CuO and (Ca, Sr)TiO3 secondary phases in the grain boundaries, which improved the grain resistance and the grain boundary resistance (Rgb) by increasing the grain boundary density. Moreover, the CCTO ceramics with 6 mol% SrO addition exhibited a high Eb of 37.1 kV/cm and a low tanδ of 0.035 while maintaining a high dielectric constant of 2469. The enhancement in Eb was attributed to the improvement in Rgb, while the reduction in tanδ was associated with the increase in Rgb and the increase in the grain boundary activation energy. This study provides a new approach for the design of high-performance CCTO-based ceramics via the minor addition of SrO.