Influence of europium addition on microstructure and electrical properties of CCTO ceramics

CaCu₃Ti₄O₁₂ (CCTO) ceramics with different proportions of Eu₂O₃ dopant (mol%, x=0.00, 0.40 %, 0.80 %, 0.12 %, 0.18 %) were prepared by solid state conventional technique. SEM and XRD were used in the microstructural studies of the specimens; at the same time, the electrical properties and V-I characteristics of the varistor ceramics samples were investigated for varistors. Electric properties of the material were related to the internal grain which was invariable with Eu₂O₃ concentration altered. Rich copper disappeared in internal boundary of the Eu-doped CCTO samples. The highest density is acquired at 1060 □, with the maximum value reaching to 95 %. The maximum nonlinear coefficient reaches to 4.1 with the Eu₂O₃ dopant content up to 1.8 mol%. The results from the measurements showed that the dielectric constant and dielectric loss of the samples varied according to the proportion of Eu₂O₃ dopant and sintering temperature.