Influence of temperature on dielectric properties of Fe-doped CaCu3Ti4O12 ceramics

CaCu3Ti4-xFexO12 (0 <= x <= 0.2) ceramics were fabricated by a solid-state reaction method, and the dielectric properties were studied. Dielectric measurement performed at room temperature shows that with Fe content increasing from 0 to 0.2, the dielectric constant (epsilon') decreases from about 5 x 10(4) to 50 in the frequency range from 1 kHz to 1 MHz, while epsilon' of all Fe-doped samples at high temperature re-increased to a high level of 10(5) below 10 kHz, characterized by dielectric temperature spectrum. Interestingly, two dielectric relaxations named as I and II are observed with the increasing of temperature. In order to catch the intrinsic relaxation mechanism, the IBLC model and modulus approach are adopted to clarify these fantastic dielectric properties. (C) 2009 Elsevier B.V. All rights reserved.