Structural and magnetic investigation of the interfaces of Fe3O4/MgO(001) with and without NiO interlayer

DOI: 10.1103/PhysRevB.105.235436

Authors: Tobias Pohlmann (Deutsches Elektronen-Synchrotron DESY; Osnabrück University) , Florian Bertram (Deutsches Elektronen-Synchrotron DESY) , Jannis Thien (Osnabrück University) , Jari Rodewald (Osnabrück University) , Kevin Ruwisch (Osnabrück University) , Timo Kuschel (Osnabrück University) , Eugen Weschke (Helmholtz-Zentrum Berlin für Materialien und Energie) , Karsten Kuepper (Osnabrück University) , Joachim Wollschlager (Osnabrück University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review B , VOL 105

State: Published (Approved)
Published: June 2022
Diamond Proposal Number(s): 19173

Abstract: We present an investigation on the structural and magnetic properties of the interfaces of Fe 3 O 4 / MgO ( 001 ) and Fe 3 O 4 / NiO / MgO ( 001 ) by extracting cation-selective magneto-optical depth profiles by means of x-ray resonant magnetic reflectivity in combination with charge-transfer multiplet simulations of x-ray magnetic circular dichroism data. For Fe 3 O 4 / MgO ( 001 ) , the magneto-optical depth profiles at the Fe 2 + oct and the Fe 3 + oct resonant energies follow exactly the structural profile, while the magneto-optical depth profile at the Fe 3 + tet resonance is offset by 3.2 ± 1.3 Å from the interface, consistent with a B -site interface termination of Fe 3 O 4 with fully intact magnetic order. In contrast, for Fe 3 O 4 / NiO ( 001 ) , the magneto-optical depth profiles at the Fe 2 + oct and the Ni 2 + resonances agree with the structural profile, but the interface positions of the magneto-optical depth profiles at the Fe 3 + oct and the Fe 3 + tet resonances are spatially shifted by 3.3 ± 1.4 and 2.7 ± 0.9 Å, respectively, not consistent with a magnetically ordered stoichiometric interface. This may be related to an intermixed ( Ni , Fe ) O layer at the interface. The dichroic depth profile at the Ni L 3 edge might hint at uncompensated magnetic moments throughout the NiO film.

Journal Keywords: Crystal stoichiometry; Surface & interfacial phenomena; Antiferromagnets; Ferrimagnets; Single crystal materials; Solid-solid interfaces; Spinels; Molecular beam epitaxy; X-ray magnetic circular dichroism; X-ray reflectivity

Diamond Keywords: Ferromagnetism; Antiferromagnetism

Subject Areas: Materials, Physics


Instruments: I10-Beamline for Advanced Dichroism - scattering

Other Facilities: UE46_PGM-1 at HZB

Added On: 01/07/2022 09:29

Discipline Tags:

Surfaces Quantum Materials Physics Hard condensed matter - structures Magnetism Materials Science interfaces and thin films

Technical Tags:

Spectroscopy Circular Dichroism (CD) X-ray Absorption Spectroscopy (XAS) X-ray Magnetic Circular Dichroism (XMCD)