Dielectric Response of Sr Doped CaCu₃Ti₄O₁₂ Ceramics

Ca1−xSrxCu3Ti4O12 (x=0, 0.1, and 0.2) ceramics were fabricated and their dielectric properties were investigated. It was found that the dielectric constant significantly decreased with the increase of Sr content at low temperature region (\u3c250 K) and remained almost unchanged at high temperature region (\u3e250 K). Three sets of relaxation peaks were observed in electric modulus plots, which were considered to be associated with grains, domain boundaries, and grain boundaries, respectively. Through the analysis of the heights and calculated activation energies of the relaxation peaks, it is strongly believed that the suppressed dielectric constant is related to the change of domain boundaries with Sr doping. ©2007 American Institute of Physic