Single-crystal oxide substrate dependent electrical properties of sputtered BiFeO3 thin films

Abstract

A series of BiFeO3 thin films were prepared on SrRuO3-buffered (100) YAlO3, (La, Sr)(Al, Ta)O3, SrTiO3 and LaAlO3 single-crystal oxide substrates via radio-frequency magnetron sputtering. An excellent (00l)-oriented growth of BiFeO3 films with a dominant rhombohedral-like phase was identified by XRD analyses. The electrical properties, e.g. dielectric, ferroelectric and leakage current characteristics, of BiFeO3 films grown on these single-crystal substrates showed significant differences. It was found that the BiFeO3 film deposited on LaAlO3 substrate exhibited the best overall electrical properties among the four films. It showed low loss tangent (tanδ<0.05) and leakage current density (J<8×10−4A/cm2), as well as a remnant polarization of 2Pr~150μC/cm2 and a reduced coercive field of 2Ec~340kV/cm.