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Spectroscopic investigation of UFe<sub>2</sub>Si<sub>2</sub>, URu<sub>2</sub>Si<sub>2</sub>, UNi<sub>2</sub>Si<sub>2</sub>, and UPd<sub>2</sub>Si<sub>2</sub>: from Pauli paramagnetism to antiferromagnetism via the hidden order state.

ORAL

Abstract

We have carried out hard x-ray photoelectron spectroscopy (HAXPES) measurements at the U 4f core level and non-resonant inelastic x-ray scattering (NIXS) at the U O4,5 edge of UT2Si2 compounds that all form in the tetragonal ThCr2Si2 structure but exhibit different ground state properties: UFe2Si2 is a Pauli paramagnet; URu2Si2 is the famous hidden order compound of which the order parameter is still fiercely debated despite 30 years of intense experimental and theoretical studies [1]; UPd2Si2 and UNi2Si2 are antiferromagnets with TN well above 100 K and sizeable ordered magnetic moments [2].
We have determined the degree of the 5f-electron localization (HAXPES [3]) as well as the symmetry of the 5f ground state wave function (NIXS [4]) across these very different compounds. This enabled us to identify their systematics and to place them in an effective Doniach phase diagram.
[1] see e.g. references in J.A. Mydosh and P.M. Oppeneer in Rev. Mod. Phys. 83, 1301{1322 (2011) and in Phil. Magazine 94, 3642 (2014).
[2] see e.g. references in T. Endstra et al, PRB 48, 9595 (1993)
[3] see M. Sundermann et al, J. Elec. Spec. & Rel. Phen. 209, 1 (2016)
[4] see M. Sundermann et al. PNAS 113, 13989 (2016)

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Presenters

  • Andrea Severing

    Institute of Physics II, University of Cologne, Physics 2, University of Cologne, Germany, University of Cologne

Authors

  • Andrea Severing

    Institute of Physics II, University of Cologne, Physics 2, University of Cologne, Germany, University of Cologne

  • Andrea Amorese

    Max-Planck Institute for Chemical Physics of Solids Dresden

  • Martin Sundermann

    Institute of Physics II, University of Cologne, Physics 2, University of Cologne, Germany, Max Planck Institute for Chemical Physics of Solids

  • Maurits Haverkort

    Institute for Theoretical Physics, Heidelberg University, Institute for theoretical physics, Institute of Theoretical Physics, University of Heidelberg, Theoretical Physics, Heidelberg University, Germany, Heidelberg University

  • Yingkai Huang

    van der Waals Zeeman Institute, Amsterdam University

  • Maria Szlawska

    Polish Acadademy of Science

  • Dariusz Kaczorowski

    Polish Academy of Sciences, Polish Acadademy of Science, Institute of Low Temperature and Structure Research, Polish Acad. of Sci.

  • Ran Sheng

    Departement of Physics, University fo California, San Diego

  • M Brian Maple

    Department of Physics, University of California, San Diego, UCSD, University of California, San Diego, physics, University of Califormia, San Diego, Departement of Physics, University fo California, San Diego, Physics, University of California, San Diego

  • Eric Bauer

    Los Alamos National Laboratory, Los Alamos Natl Lab, Condensed Matter and Magnet Science Group, Los Alamos National Laboratory, Los Alamos National Laboratory, Los Alamos

  • Andreas Leithe-Jasper

    Max-Planck Institute for Chemical Physics of Solids Dresden, Max Planck Institute for Chemical Physics of Solids

  • Liu Tjeng

    Max Planck Inst, Max-Planck Institute for Chemical Physics of Solids Dresden, Max Planck Institute for Chemical Physics of Solids, Dresden, Germany, Max Planck Institute for Chemical Physics of Solids