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/
L
1
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
.