Itinerant antiferromagnetism and its manifestation in the spin dynamics of SrCr2As2

ORAL

Abstract

Neutron diffraction and magnetic susceptibility studies of polycrystalline SrCr2As2 reveal that this compound is an itinerant G-type antiferromagnet below the Neel temperature TN = 590(5) K with the Cr magnetic moments aligned along the tetragonal c axis. The system remains tetragonal to the lowest measured temperature (~12 K). The ordered moment, μ = 1.9(1) μB/Cr, measured at T = 12 K, is significantly reduced compared to its localized value (4 μB/Cr) due to the itinerant character brought about by hybridization between the Cr 3d and As 4p orbitals. Inelastic neutron scattering measurements on powder samples show steep columns of magnetic scattering arising from the magnetic Γ points, with the magnetic spectra persisting up to at least 150 meV. The spectra are modeled using a phenomenological J1-J2-Jc Heisenberg description with very large nearest- (J1) and next-nearest-neighbor (J2) AFM interactions within the square tetragonal basal plane and weak interlayer interactions (Jc).

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Presenters

  • Pinaki Das

    Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames Laboratory/Iowa State University

Authors

  • Pinaki Das

    Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames Laboratory/Iowa State University

  • N.S. Sangeetha

    Ames Laboratory, Iowa State University

  • G.R. Lindemann

    Ames Laboratory, Iowa State University

  • Tom Heitmann

    The Missouri Research Reactor, University of Missouri, Research Reactor Center, Univ of Missouri - Columbia

  • Douglas Abernathy

    Oak Ridge National Laboratory, Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge National Lab

  • Andreas Kreyssig

    Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames Laboratory/Iowa State University, Iowa State University, Ames Laboratory and Iowa State University, Dept. of Physics and Astronomy, Dept. of Physics, Iowa State Univ, Ames Lab

  • David Johnston

    Ames Laboratory, Iowa State University

  • Alan Goldman

    Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames Laboratory/Iowa State University, Iowa State University, Dept. of Physics, Iowa State Univ

  • Robert McQueeney

    Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames Laboratory/Iowa State University, Iowa State University, Ames Laboratory and Iowa State University, Dept. of Physics and Astronomy

  • David Vaknin

    Ames Laboratory, Iowa State University