title: Stable room-temperature ferromagnetic phase at the FeRh(100) surface.
abstract: Interfaces and low dimensionality are sources of strong modifications of electronic, structural, and magnetic properties of materials. FeRh alloys are an excellent example because of the first-order phase transition taking place at ~400 K from an antiferromagnetic phase at room temperature to a high temperature ferromagnetic one. It is accompanied by a resistance change and volume expansion of about 1%. We have investigated the electronic and magnetic properties of FeRh(100) epitaxially grown on MgO by combining spectroscopies characterized by different probing depths, namely X-ray magnetic circular dichroism and photoelectron spectroscopy. We find that the symmetry breaking induced at the Rh-terminated surface stabilizes a surface ferromagnetic layer involving five planes of Fe and Rh atoms in the nominally antiferromagnetic phase at room temperature. First-principles calculations provide a microscopic description of the structural relaxation and the electron spin-density distribution that support the experimental findings.
authors.affiliation: Synchrotron-SOLEIL, Saint-Aubin, BP 48, F-91192 Gif sur Yvette Cedex, France.
authors.forename: Federico
authors.initials: F
authors.lastname: Pressacco
authors.affiliation: Center for Memory and Recording Research, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0401, USA.
authors.forename: Vojtěch
authors.initials: V
authors.lastname: Uhlίř
authors.affiliation: Laboratoire des Solides Irradiés, École Polytechnique, CNRS, CEA-DSM-IRAMIS, Université Paris-Saclay, F-91128 Palaiseau, France.|European Theoretical Spectroscopy Facility (ETSF), F-91128 Palaiseau, France.
authors.forename: Matteo
authors.initials: M
authors.lastname: Gatti
authors.affiliation: Synchrotron-SOLEIL, Saint-Aubin, BP 48, F-91192 Gif sur Yvette Cedex, France.
authors.forename: Azzedine
authors.initials: A
authors.lastname: Bendounan
authors.affiliation: Center for Memory and Recording Research, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0401, USA.
authors.forename: Eric E
authors.initials: EE
authors.lastname: Fullerton
authors.affiliation: Synchrotron-SOLEIL, Saint-Aubin, BP 48, F-91192 Gif sur Yvette Cedex, France.
authors.forename: Fausto
authors.initials: F
authors.lastname: Sirotti