Magnetic anisotropic of thermally evaporated FeNi thin film: A soft X‐ray magnetic circular dichroism study

Abstract

FeNi film was fabricated on Cu/MgO (001) substrates using thermal evaporation technique of a FeNi target to realize the formation of an L10‐FeNi phase. The magnetic anisotropy of FeNi film was systematically investigated by means of X‐ray absorption spectroscopy (XAS) and X‐ray magnetic circular dichroism (XMCD) techniques. Our L‐edge XAS and XMCD analysis is performed for 30‐nm FeNi film grown on Cu/MgO (001) substrate. The present experimental results of XAS and XMCD indicate that ~5% Fe atoms are oxidized. Our findings also showed that the orbital magnetic moment of Fe has a significant incident X‐ray angle dependence that exhibits a maximum value at the out‐of‐plane direction corresponding perpendicular to the plane. The origin of anisotropy is successfully explained by element‐specific XMCD technique. The enhancement in magnetic anisotropy energy (MAE) is due to orbital magnetic moments of Fe through spin–orbit interaction. The uniaxial anisotropy energy showed quantitatively good agreement with the volume MAE.

Microscopic evaluation of orbital moment in ferromagnetic resonance

“…The disappearance of m L component in the XFMR data can be attributed to the principal direction of m L , which is preferably oriented normal to the sample surface in a thin film sample. Theoretical and experimental investigation of 3d magnetic thin film samples have provided evidence of the perpendicular m L induced by d-d hybridization via SO coupling, which results in a perpendicular magnetic anisotropy (PMA) 2, [47][48][49] . Furthermore, in a multilayered system comprising 3d magnetic metal and 5d non-magnetic metal with strong SO coupling, 3d-5d hybridization at the interface enhances the perpendicular m L , further driving PMA [50][51][52] .…”