Unexpected dielectric response in lead zirconate titanate ceramics: The role of ferroelectric domain wall pinning effects

Temperature dependent dielectric response has been measured in Pb(Zr1-xTix)O-3 ceramics. Samples of different compositions (x=0.40, 0.47, and 0.60), pure and doped with Nb-or Fe, were studied at temperatures between 15 and 700 K and in the frequency range from 100 Hz to 1 MHz. Unexpected dielectric behavior has been found around room temperature. Anomalous temperature dependent permittivity is observed in pure and Fe-doped samples but not in Nb-doped samples. The anomaly appears related to the presence of oxygen vacancies but not on the sample crystallographic phase. The authors suggest that the anomaly may be a manifestation of the domain wall pinning effect. (C) 2007 American Institute of Physics.Peer Reviewe