Magnetic properties of manganese ferrite films grown at atomic scale

Abstract

Manganese ferrite is a partial inverse spinel which, when prepared by conventional growth techniques, has ∼20% of the Mn2+ ions on the octahedral sublattice. Here we describe a layer–by–layer growth scheme at atomic scale by which the percentage of Mn2+ ions on the octahedral sublattice can be artificially controlled. Manganese ferrite films grown by this technique exhibits different degrees of cation inversion when grown on {100} and {111} MgO substrates. It was observed that saturation magnetization varied in a wide range of values depending on chemical composition and oxygen pressure. Although bulk manganese ferrite was low anisotropy magnetic material, uniaxial anisotropy was observed at room temperature in the films deposited on {100} MgO substrates, and its magnitude and direction sensitively depended on chemical composition and oxygen pressure during deposition.