Improved dielectric properties of indium and tantalum co-doped CaCu3Ti4O12 ceramic prepared by spark plasma sintering

摘要

The current-voltage characteristics and dielectric properties of indium and/or tantalum doped CaCu3Ti4O12 (CCTO) ceramics prepared by spark plasma sintering are investigated in this work. The X-ray diffraction patterns reveal the formation of pure cubic perovskite CCTO with no impurity phase. The grain size is suppressed by doping In and Ta, and the densification of the CCTO ceramics is achieved, showing a relative density of about 97.5%. The approach of 0.5 mol% In and Ta co-doping results in enhanced energy density and electrical properties. The energy density is increased by more than 30 % and the breakdown field Eb is improved to 9.67 kV/cm. Similarly, the lowest dielectric loss of 0.024 at nearly 1 kHz can be obtained in the co-doped sample, which can be attributed to the enhancement of the conductance activation energy and Schottky barrier height.