Interface magnetic anisotropy between L1 ₀ -FePt and nonmagnetic layers

In order to examine the interface magnetic anisotropy at the interface between an L1 ₀-FePt layer and a nonmagnetic layer, the magnetic properties for thin films with Au buffer/L1 ₀-FePt/ capping layers were investigated, where MgO or Au was used as a capping layer. When the thickness of the L1 ₀-FePt layer (t _FePt}) was reduced from 5 nm to 1.5 nm, MgO-capped L1 ₀-FePt showed larger perpendicular magnetic anisotropy than those of Au-capped L1 ₀ -FePt and uncapped L1 ₀-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 L1 ₀ -FePt and MgO layers, value of which was estimated to be 630 μJ/m ².