Ferroelectric domain structure of Bi2FeCrO6 multiferroic thin films

Abstract

Bi2FeCrO6 (BFCO) multiferroic thin films were deposited on SrRuO3(SRO)/SrTiO3(STO) (001) and STO (001) substrates by a pulsed laser deposition method. High-quality epitaxial BFCO thin films with a typical step-flow surface morphology were successfully prepared. X-ray diffraction reveals that the high phase-purity epitaxial BFCO films with good crystallinity are obtained. Using both piezoelectric force microscopy (PFM) and x-ray reciprocal space mapping, we studied the ferroelectric domain structure and ferroelectricity characterization of BFCO thin films with and without an SRO buffer layer. The ferroelectric domain structure of an epitaxial BFCO film deposited on SRO/STO (001) is characterized by eight polarization variants. However, the ferroelectric domain structure of the epitaxial BFCO film directly grown on the STO (001) substrate is degenerate from eight polarization variants to four or even two. The feasibility of ferroelectric domain engineering is demonstrated by growing BFCO films on STO (001) with and without SRO buffer layers.