Detwinning Monoclinic Phase BiMnO₃Thin Film

Abstract

BiMnO 3 has been a promising candidate as a magnetoelectric multiferroic while there have been many controversial reports on its ferroelectricity. The detailed analysis of its film growth, especially the growth of thin film having monoclinic symmetry has not been reported. We studied the effect of miscut angle, the substrate surface, and film thickness on the symmetry of BiMnO 3 thin film. A flat SrTiO 3 (110) substrate resulted in a thin film with three domains of BiMnO 3 and 1 degree miscut in the SrTiO 3 (110) substrate resulted in dominant domain preference in the BiMnO 3 thin film. The larger miscut resulted in a nearly perfect detwinned BiMnO 3 film with a monoclinic phase. This strong power of domain selection due to the step edge of the substrate was efficient even for the thicker film which showed a rather relaxed growth behavior along the SrTiO 3 [1-10] direction.