Epitaxial stabilization and structural properties of REMnO3 (RE=Dy,Gd,Sm) compounds in a layered, hexagonal ABO3 structure

RE Mn O 3 (RE=Dy,Gd,Sm) films were deposited on (110) surfaces of single crystalline hexagonal (h-)YMnO3. These films adopted the metastable multiferroic h-REMnO3 structure instead of the stable perovskite structure. Sharp (hh0) diffraction peaks with narrow rocking curves were found for all films. The peak widths increased with increasing size of the rare-earth cation. The c-axis/a-axis lattice parameter decreased/increased monotonically with increasing rare-earth size for these epitaxial films. All films exhibited the following epitaxial relationship {110}REMnO3‖{110}YMnO3;⟨11¯0⟩REMnO3‖⟨11¯0⟩YMnO3. The single-phase hexagonal films were kinetically robust against back transformation to the stable perovskite structure even to thicknesses of 50nm.