Origin of strong magnetic anisotropy in L10-FeNi probed by angular-dependent magnetic circular dichroism

► Origin of strong magnetic anisotropy in L10-FeNi is investigated. ► Clear angular distribution is found only in the Fe orbital magnetic moment. ► Magnetic anisotropy is calculated based on spin-orbit interaction. ► Calculated value quantitatively agrees with volume magnetic anisotropy. ► Orbital anisotropy of Fe 3D is the origin of strong magnetic anisotropy in L10-FeNi.