Interface Magnetic Anisotropy Between L1 $_{0}$ -FePt and Nonmagnetic Layers

In order to examine the interface magnetic anisotropy at the interface between an L1₀-FePt layer and a nonmagnetic layer, the magnetic properties for thin films with Au buffer/L1₀-FePt/capping layers were investigated, where MgO or Au was used as a capping layer. When the thickness of the L1₀-FePt layer (t_FePt) was reduced from 5 nm to 1.5 nm, MgO-capped L1₀-FePt showed larger perpendicular magnetic anisotropy than those of Au-capped L1₀-FePt and uncapped L1₀-FePt. The plot of the magnetic anisotropy energy per sheet area as a function of t_FePt suggested that the existence of the interface magnetic anisotropy between L1₀ -FePt and MgO layers, value of which was estimated to be 630 μJ/m².