Magnetic properties of monocrystalline epilayer sandwich of magnesium ferrite

The ferrimagnetic monocrystalllne epilayer Mg0.5Fe2.5O4and superparamagnetic interface between this layer at the MgO monocrystalline substrate formed the sandwich. The sandwich was obtained by CVD on the /100/ crystallographical surface of the substrate. The magnetic properties of this sandwich were studied by ferromagnetic resonance. Measurements at room temperature at 9.26, 25.94, 33.04 and 69.61 GHz permitted the determination of the resonance field Hrvs. the angle θ between the normal to the layer and the external field direction in the crystallographical plane /010/. In this data was defined the magnetic parameters characterizing the two layers of the sandwich as functions of the microwave frequency. Epilayer Mg0.5Fe2.5O4exhibited at ferromagnetic resonance non-collinearity between its magnetisation and the external field dependent on θ and frequency. The interface, of weaker magnetisation, exhibited superparamagnetic properties - the magnetisation increased with increasing microwave frequency.