Microstructure of the thin iron films with perpendicular magnetic anisotropy

Using high-resolution transmission electron microscopy and magnetometry we studied microstructure of the thin iron films with perpendicular magnetic anisotropy (PMA) and without it, formed by ion beam assisted deposition technique. It was established that iron films with PMA unlike films without PMA are nanocomposite film comprising iron nanoparticles with size 4–5 nm and paramagnetic iron oxide (FeO and Fe$_2$O$_3$). In general the data obtained indicate that the key role in PMA belongs to nanocomposite structure of films with weak exchange-coupled ferromagnetic nanoparticles of iron in paramagnetic matrix.