Correlation between crystal structure and magnetism in PLD grown epitaxial films of ε-FeO on GaN.

In the present paper we discuss correlations between crystal structure and magnetic properties of epitaxial ε-FeO films grown on GaN. The large magnetocrystalline anisotropy and room temperature multiferroic properties of this exotic iron oxide polymorph, make it a perspective material for the development of low power consumption magnetic media storage devices. Extending our recent progress in PLD growth of ε-FeO on the surface of technologically important nitride semiconductors, we apply reciprocal space tomography by electron and x-ray diffraction to investigate the break of crystallographic symmetry occurring at the oxide-nitride interface resulting in the appearance of anisotropic crystallographic disorder in the sub-100 nm ε-FeO films.