Manganese ferrite grown at the atomic scale

Manganese spinel ferrite (MnFe₂O₄) films were deposited at the atomic scale. In the depositions, laser pulses alternately impinged MnO and Fe₂O₃ targets and sequentially deposited thin layers (∼5 Å) of MnO and Fe₂O₃ on MgO substrate, which is referred to as "artificial" films. The X-ray diffraction measurements showed that the artificial films were of spinel structure. Auger spectroscopy measurements showed that the chemical composition of the artificial ferrites were consistent with that of standard films deposited using a single target of MnFe₂O₄. However, extended X-ray absorption fine spectroscopy showed that the artificial growth technique affected the cation distribution to be different from the standard films. As a result, the magnetic properties of the artificial films, including Ne´el temperature, uniaxial and in-plane anisotropy, were different from the standard films.