Strength of Perpendicular Magnetic Anisotropy at Bottom and Top Interfaces in [Pt/Co/Pt] Trilayers

The individual strengths of perpendicular magnetic anisotropy (PMA) at the bottom and top interfaces in sputtered [Pt/Co/Pt] trilayers are determined. The PMA strength from the top Co/Pt interface is significantly weaker than that from the bottom Pt/Co interface, indicating a similar difference in the interface quality. The contribution to the total anisotropy strength from the top Co/Pt interface increases with decreasing top Pt layer thickness; for a stack of Co thickness 1 nm, the contribution is only 10% for a top Pt layer of thickness 3.0 nm, but it increases to 32% for a Pt layer of thickness 0.2 nm.