Nanoscale spatial switching of magnetic anisotropy in pseudomorphic Fe(110) on W(110)

Pseudomorphic Fe(110) films, prepared on W(110) at room temperature, with a mean thickness of roughly 1.5 monolayers, consist of double-layer islands with a diameter of the order of 10 nm which are ferromagnetic (superparamagnetic) at room temperature, surrounded by a monolayer sea which becomes ferromagnetic below 222 K. Magnetic anisotropy is uniaxial in both components, but the easy axis spatially switches between perpendicular to the plane for the islands and in the plane for the monolayer sea. The intimate interconnection of exchange coupled components with orthogonal anisotropies induces a rich variety of new micromagnetic phenomena.