Relative strength of perpendicular magnetic anisotropy at bottom and top interfaces in Pt/Co/MgO trilayers

In Pt/Co/MgO trilayers, the contribution to the total perpendicular magnetic anisotropy from the bottom Pt/Co interface is significantly greater than that from the top Co/MgO interface at intermediate annealing temperatures. However, the relative contribution is reversed at the highest annealing temperature examined in this study, 400 °C. These results indicate that as the annealing temperature increases, the quality of the Pt/Co interface deteriorates owing to the intermixing of Pt and Co, whereas the quality of the Co/MgO interface improves as oxygen atoms, which are interpenetrated into the Co layer during the deposition of MgO, are diffused toward the Co/MgO interface.