title: Static Magnetic Proximity Effect in Pt/NiFe2O4 and Pt/Fe Bilayers Investigated by X-Ray Resonant Magnetic Reflectivity.
abstract: The spin polarization of Pt in Pt/NiFe2O4 and Pt/Fe bilayers is studied by interface-sensitive x-ray resonant magnetic reflectivity to investigate static magnetic proximity effects. The asymmetry ratio of the reflectivity is measured at the Pt L3 absorption edge using circular polarized x-rays for opposite directions of the magnetization at room temperature. The results of the 2% asymmetry ratio for Pt/Fe bilayers are independent of the Pt thickness between 1.8 and 20 nm. By comparison with ab initio calculations, the maximum magnetic moment per spin polarized Pt atom at the interface is determined to be (0.6±0.1)  μB for Pt/Fe. For Pt/NiFe2O4 the asymmetry ratio drops below the sensitivity limit of 0.02  μB per Pt atom. Therefore, we conclude, that the longitudinal spin Seebeck effect recently observed in Pt/NiFe2O4 is not influenced by a proximity induced anomalous Nernst effect.
authors.affiliation: Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Kuschel
authors.affiliation: Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Klewe
authors.affiliation: Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany.
authors.forename: J-M
authors.initials: JM
authors.lastname: Schmalhorst
authors.affiliation: Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Bertram
authors.affiliation: Fachbereich Physik, Universität Osnabrück, Barbarastraße 7, 49069 Osnabrück, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Kuschel
authors.affiliation: Fachbereich Physik, Universität Osnabrück, Barbarastraße 7, 49069 Osnabrück, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Schemme
authors.affiliation: Fachbereich Physik, Universität Osnabrück, Barbarastraße 7, 49069 Osnabrück, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Wollschläger
authors.affiliation: Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Francoual
authors.affiliation: Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Strempfer
authors.affiliation: Center for Materials for Information Technology, University of Alabama, Tuscaloosa, Alabama 35487, USA.
authors.forename: A
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Meinert
authors.affiliation: Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Götz
authors.affiliation: Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Meier
authors.affiliation: Center for Spinelectronic Materials and Devices, Department of Physics, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Reiss