Multiferroic Properties and Leakage Current Mechanisms of ${\rm Bi}_{0.9}{\rm Eu}_{0.1}{\rm FeO}_{3}$ Thin Films

Bi_0.9Eu_0.1FeO₃ (BEFO) thin films were deposited on Pt(111)/Ti/SiO₂/Si(100) substrates using the sol-gel method and rapid thermal annealing in an oxygen atmosphere. The effects of annealing temperature (400 ~ 700 C) on microstructure and multiferroic properties of thin films were investigated. The X-ray diffraction analysis showed that the BEFO thin films had an orthorhombic structure. The thin films showed ferroelectric and ferromagnetic properties with remanent polarization (2P_r) of 15 μC/cm² and remnant magnetization (2Mr) of 4.2 emu/g. The leakage current density (J) of the BEFO thin film annealed at 700 ^°C was 4.25×10^-8& A/cm² at 150 kV/cm. The leakage current was affected not only by the microstructure but also by the interface between the Pt electrode and the BEFO thin films. Moreover, it was found that more than one conduction mechanism was involved in the electric field range used in these experiments. In the low electric field region, the leakage current was controlled by Poole-Frenkel emission. However, the mechanism could be explained by Schottky emission from the Pt electrode in the high electric field region.