Structural properties and polarization switching of epitaxial Bi2FeCrO6 thin films grown on La2/3Sr1/3MnO3/SrTiO3 (111) substrates

Ferroelectric Bi2FeCrO6 (BFCO) double perovskite thin films were grown by pulsed laser deposition on SrTiO3 (111) covered with a 20 nm thick La2/3Sr1/3MnO3 buffer layer. X-ray diffraction measurements performed in θ-2θ and φ scans modes reveal an epitaxial growth of the BFCO with a compressive in-plane strained structure and no spurious phases. The presence of superstructure diffraction peaks indicates an Fe-Cr cationic ordering along the growth axis. Local measurements realized by piezo-response force microscopy show an asymmetric polarization switching with respect to the external bias voltage suggesting the presence of a bias field. This agrees with a preferential ferroelectric polarization observed upon local poling of the BFCO film in opposite directions. The findings can be of importance for understanding the relationship between the atomic structure and polarization dynamics in ferroelectric thin-films. © 2022 Elsevier B.V.