Dielectric loss anomaly in Ba(Fe1/2Ta1/2)O3 ceramics

The dielectric loss relaxation characteristic of Ba(Fe1/2Ta1/2)O-3 ceramics, which has cubic perovskite structure, was studied. The frequency dependence of dielectric loss, dielectric loss tangent and electric modulus were analyzed in the frequency range from 20 Hz to 1 MHz by changing the temperature up to 372 K. Complex impedance spectroscopy technique was also used to examine the dielectric characteristics. A Debye-like dielectric loss relaxation was observed around room temperature, which was not reported so far. Its activation energy was 0.15 eV and the relaxation time was 10(-7) s. The Debye-like dielectric loss relaxation was explained by the different thermal motion of B-site ions. (C) 2002 Published by Elsevier Science B.V.