Dielectric dispersion of BiFeO3 thin film over a broad frequency range (100 Hz–10 GHz)

Abstract

The dielectric properties of single-phase BiFeO3 (BFO) thin films were investigated based on parallel-plate electrode (PPE) and coplanar interdigital electrode (CIE) configurations across a wide frequency range of 100 Hz–10 GHz. The dielectric dispersion in the PPE configuration, caused by the interfacial polarization in film/electrode interfaces, exhibited a strong dependence on frequency. In the CIE configuration, the low dielectric dispersion, high permittivity, and low dielectric loss indicated that interfacial polarization was substantially suppressed, revealing the dielectric properties of BFO film. Analysis of its electrical behavior demonstrated that Poole–Frenkel emission dominated the leakage current mechanism in the symmetric electrode structure.