Effects of interfacial polarization on the dielectric properties of BiFeO3 thin film capacitors

Abstract

Epitaxial BiFe O3 La0.7 Sr0.3 Mn O3 (BFO/LSMO) heterostructures were grown on SrTi O3 (001) substrates. Dielectric properties of the BFO thin films were investigated in an In/BFO/LSMO capacitor configuration. The capacitance of the capacitor shows strong dependences on measuring frequency and bias voltage especially in low frequency region (≤1 MHz). By means of complex impedance analysis, it is found that the interfacial polarization caused by space charges in the film/electrode interfaces plays an important role in the dielectric behavior of the capacitor. Our results indicate that the influences of film/electrode interfaces might not be neglected on the dielectric properties of the BFO thin film capacitors. © 2008 American Institute of Physics.