Depth profile of the Fe spin and orbital magnetic moments in a V/Fe/MgO trilayer revealed by depth-resolved x-ray magnetic circular dichroism

摘要

Fe/MgO interfaces are one of the most important ingredients in spintronics devices because they showstrong interfacial perpendicular magnetic anisotropy and because Fe/MgO-based magnetic tunnel junctionsshow a large tunneling magnetoresistance effect. To gain a deeper understanding of these phenomena, it isimportant to clarify how the Fe spin and orbital magnetic moments behave at the interface and away fromthe interface. In the present study, we performed depth-resolved x-ray magnetic circular dichroism (XMCD)[1] measurements to reveal the depth profile of spin and orbital magnetic moments in a V/Fe (0.7 nm)/MgOtrilayer. The trilayer was grown by molecular beam epitaxy method. The sample structure is schematicallyshown in Fig. 1(a). The depth-resolved XMCD measurements were performed at BL-7A of the PhotonFactory. Figure 1(b) shows x-ray absorption spectroscopy (XAS) spectrum and XMCD spectrum taken atroom temperature with total electron yield mode. The spectra look similar to those reported in a previousstudy [2]. In the presentation, we will report the depth profile of the spin and orbital magnetic moments andcompare the results with density-functional-theory calculations.