Depth-Resolved XMCD Application to Fe/Ni/Cu(001) Films

摘要

Spin reorientation transitions (SRTs) of Ni/Cu(001) induced by Fe depositions were investigated using x-ray magnetic circular dichroism (XMCD) method. In-plane magnetized Ni films (<9 ML) exhibited the SRT twice; first, a small deposition (<1 ML) of Fe caused a transition to perpendicular magnetization. Second, further Fe deposition (1 to 2 ML in total) caused a return to in-plane magnetization. Perpendicularly magnetized Ni films (>10 ML) also exhibited a transition to in-plane by 1 to 2 ML Fe deposition. The Fe orbital to spin magnetic moment ratio in 2 ML were investigated with the depth-resolved XMCD technique, leading to the results that the top layer had a large orbital to spin magnetic moment ratio for perpendicular direction, while the bottom layer had a large orbital to spin magnetic moment ratio for in-plane direction. Magnetic anisotropy energies of Fe were determined in the depth-resolved way from the moment analyses. The mechanisms of the SRTs were successfully explained by the obtained magnetic anisotropy energies.