Abstract

The magnetic anisotropy (MA) of Fe-based ferromagnetic thin films has been extensively studied for device applications. The examined material is a new Fe-based ferromagnetic thin film, bcc Fe₁-xAsx (Fe-As) with the in-plane MA (IMA) grown on a GaAs (111)B substrate. The magnetic properties of the Fe-As thin film have been investigated by X-ray magnetic circular dichroism (XMCD) and magnetic circular dichroism in hard X-ray photoemission spectroscopy (MCD-HAXPES) to elucidate the role of As ions in the IMA. The XMCD spectra at the Fe L2,3 edge and MCD-HAXPES spectra of the Fe 2p core level exhibit ferromagnetic and metallic features like Fe metal. The XMCD at the As L2,3 edge demonstrates that the As ions contribute to the ferromagnetism of bcc Fe-As through the hybridization between the Fe 3d and As 4p orbitals. The estimations of the magnetic moments of Fe using the XMCD sum rules have revealed that the orbital magnetic moment is isotropic and the magnetic dipole term is anisotropic. The anisotropy of the magnetic dipole term can be attributed to the anisotropic p-d hybridization due to epitaxial strain, contributing to the IMA of bcc Fe-As. Our findings enlighten the mechanism of the MA of the non-magnetic ion-doped bcc Fe thin film, which can be applied to other magnetic 3d transition metal thin films doped with non-magnetic elements.

Abstract

The magnetic anisotropy (MA) of Fe-based ferromagnetic thin films has been extensively studied for device applications. The examined material is a new Fe-based ferromagnetic thin film, bcc Fe₁-xAsx (Fe-As) with the in-plane MA (IMA) grown on a GaAs (111)B substrate. The magnetic properties of the Fe-As thin film have been investigated by X-ray magnetic circular dichroism (XMCD) and magnetic circular dichroism in hard X-ray photoemission spectroscopy (MCD-HAXPES) to elucidate the role of As ions in the IMA. The XMCD spectra at the Fe L2,3 edge and MCD-HAXPES spectra of the Fe 2p core level exhibit ferromagnetic and metallic features like Fe metal. The XMCD at the As L2,3 edge demonstrates that the As ions contribute to the ferromagnetism of bcc Fe-As through the hybridization between the Fe 3d and As 4p orbitals. The estimations of the magnetic moments of Fe using the XMCD sum rules have revealed that the orbital magnetic moment is isotropic and the magnetic dipole term is anisotropic. The anisotropy of the magnetic dipole term can be attributed to the anisotropic p-d hybridization due to epitaxial strain, contributing to the IMA of bcc Fe-As. Our findings enlighten the mechanism of the MA of the non-magnetic ion-doped bcc Fe thin film, which can be applied to other magnetic 3d transition metal thin films doped with non-magnetic elements.

Abstract

The magnetic anisotropy (MA) of Fe-based ferromagnetic thin films has been extensively studied for device applications. The examined material is a new Fe-based ferromagnetic thin film, bcc Fe₁-xAsx (Fe-As) with the in-plane MA (IMA) grown on a GaAs (111)B substrate. The magnetic properties of the Fe-As thin film have been investigated by X-ray magnetic circular dichroism (XMCD) and magnetic circular dichroism in hard X-ray photoemission spectroscopy (MCD-HAXPES) to elucidate the role of As ions in the IMA. The XMCD spectra at the Fe L2,3 edge and MCD-HAXPES spectra of the Fe 2p core level exhibit ferromagnetic and metallic features like Fe metal. The XMCD at the As L2,3 edge demonstrates that the As ions contribute to the ferromagnetism of bcc Fe-As through the hybridization between the Fe 3d and As 4p orbitals. The estimations of the magnetic moments of Fe using the XMCD sum rules have revealed that the orbital magnetic moment is isotropic and the magnetic dipole term is anisotropic. The anisotropy of the magnetic dipole term can be attributed to the anisotropic p-d hybridization due to epitaxial strain, contributing to the IMA of bcc Fe-As. Our findings enlighten the mechanism of the MA of the non-magnetic ion-doped bcc Fe thin film, which can be applied to other magnetic 3d transition metal thin films doped with non-magnetic elements.

Abstract

The magnetic anisotropy (MA) of Fe-based ferromagnetic thin films has been extensively studied for device applications. The examined material is a new Fe-based ferromagnetic thin film, bcc Fe₁-xAsx (Fe-As) with the in-plane MA (IMA) grown on a GaAs (111)B substrate. The magnetic properties of the Fe-As thin film have been investigated by X-ray magnetic circular dichroism (XMCD) and magnetic circular dichroism in hard X-ray photoemission spectroscopy (MCD-HAXPES) to elucidate the role of As ions in the IMA. The XMCD spectra at the Fe L2,3 edge and MCD-HAXPES spectra of the Fe 2p core level exhibit ferromagnetic and metallic features like Fe metal. The XMCD at the As L2,3 edge demonstrates that the As ions contribute to the ferromagnetism of bcc Fe-As through the hybridization between the Fe 3d and As 4p orbitals. The estimations of the magnetic moments of Fe using the XMCD sum rules have revealed that the orbital magnetic moment is isotropic and the magnetic dipole term is anisotropic. The anisotropy of the magnetic dipole term can be attributed to the anisotropic p-d hybridization due to epitaxial strain, contributing to the IMA of bcc Fe-As. Our findings enlighten the mechanism of the MA of the non-magnetic ion-doped bcc Fe thin film, which can be applied to other magnetic 3d transition metal thin films doped with non-magnetic elements.