MAXWELL—WAGNER MECHANISM INDUCED DIELECTRIC RELAXOR IN BiFeO3/Bi3.25La0.75Ti3O12 FILM.

Maxwell—Wagner (M-W) theory was used to explain the dielectric relaxor behavior of BiFeO3(BFO)/Bi3.25La0.75Ti3O12(BLT) film grown on Pt/Ti/SiO2/Si substrate. The BFO film was considered to be ferroelectric film, and its temperature dependence of dielectric constant was calculated by Landau theory. BLT film was of dielectric-relaxor behavior and its temperature dependence of dielectric constant was given by Smolenski theory. The leakage currents for the BFO and BLT films were assumed to obey Poole-Frenkel emission and Schottky emission, respectively. The temperature dependent dielectric constant and loss of the BFO/BLT film were characterized, which agrees with the experiment. The enhancement of the polarization in BFO/BLT film may induced by the current leakage restraining in BFO film. [ABSTRACT FROM AUTHOR]