Relationship between orbital moment anisotropy, magnetocrystalline anisotropy, and Dzyaloshinskii-Moriya interaction in W/Co/Pt trilayers

Chi, Z.*; 芝田 悟朗 ; 藤森 淳; 他15名*

Chi, Z.*; Shibata, Goro; Fujimori, Atsushi; 15 of others*

We have studied the Co layer thickness dependences of magnetocrystalline anisotropy (MCA), Dzyaloshinskii-Moriya interaction (DMI), and orbital moment anisotropy (OMA) in W/Co/Pt trilayers, in order to clarify their correlations with each other. We find that the MCA favors magnetization along the film normal and monotonically increases with decreasing effective magnetic layer thickness (). The magnitude of the Dzyaloshinskii-Moriya exchange constant () increases with decreasing until 1 nm, below which decreases. The MCA and scale with 1/ for larger than nm, indicating an interfacial origin. Using X-ray magnetic circular dichroism (XMCD), we find non-zero OMA when is smaller than nm. The OMA increases with decreasing more rapidly than what is expected from the MCA, indicating that factors other than OMA contribute to the MCA at small .