Effect of substrate orientation on ferroelectric behavior of monoclinic BiFeO3 thin film

We report on ferroelectric properties of the monoclinic BiFeO3 thin films grown on (001) and (110) SrTiO3 substrates. Structural analysis using X-ray diffractometer and the electrical characterization of ferroelectricity reveal that the elastic constraint induced by the crystallographic orientation affects the remnant polarization values and retention properties of BiFeO3. The in-depth analysis based on the Williamson-Hall plot and thermodynamic analysis manifests that inhomogeneous strain related to the strain relaxation in the film is responsible for the change of the out-of-plane polarization and retention property of BiFeO3 thin films depending on the substrate orientation.