Interplay between local and itinerant magnetism in transition metal oxides: the role of anion magnetism

ORAL

Abstract

Transition-metal oxides (TMOs) have been studied widely for their fascinating properties. Recently, neutron diffraction experiments and density-functional-theory (DFT) calculations found sizable magnetic moments on the oxygen anions in ferromagnetic SrRuO3. In general, using appropriate functionals, DFT captures the magnetic properties of many TMOs. Here, we report comprehensive DFT calculations in a wide range of 3d-, 4d-, and 5d-TMOs and a few sulfides, aiming to elucidate the microscopic origin of anionic magnetization. We examine the local spin density of states, radial dependence of magnetization, and strain sensitivity. Cation-anion bond lengths play a major role in controlling the degree of anionic magnetization. However, we find a complex spin-density distribution in both coordinate and energy space, whereby the simple picture of TM d-orbitals overlapping the anions is not sufficient to account for the magnitude of anion magnetic moments. Anion magnetic moments range from zero (Heisenberg ferromagnets) to values that are comparable to cation magnetic moments (itinerant ferromagnets).

*Supported by DOE grant DE-FG-02-09ER46554 and McMinn Endowment -- computations at NERSC (VU); DST-SERB Core Research Grand File No. CRG/2018/001728 -- computations at HPCC of the SRM (SRM).

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Presenters

  • Swamynadhan M. J.

    • Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur 603 203, Tamil Nadu, India
    • Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur - 603 203, Tamil Nadu, India

Authors

  • Swamynadhan M. J.

    • Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur 603 203, Tamil Nadu, India
    • Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur - 603 203, Tamil Nadu, India

  • Donghan Shin

    • Department of Physics and Astronomy, Vanderbilt Univ
    • Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235, USA
    • Department of Physics and Astronomy, Vanderbilt University

  • Andrew O'Hara

    • Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235, USA
    • Department of Physics and Astronomy, Vanderbilt University
    • Department of Physics and Astronomy, Vanderbilt University, Nashville, TN
    • Vanderbilt University

  • Saurabh Ghosh

    • Physics and Nanotechnology, SRM Institute of Science and Technology
    • Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur 603 203, Tamil Nadu, India
    • Dept. of Physics and Nanotechnology, SRM Institute of Science and Technology
    • Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur - 603 203, Tamil Nadu, India

  • Sokrates T Pantelides

    • Department of Physics and Engineering, Vanderbilt University
    • Department of Physics and Astronomy, Vanderbilt Univ
    • Department of Physics and Astronomy, Vanderbilt University
    • Vanderbilt Univ
    • Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235, USA
    • Institute of Physics, Chinese Academy of Sciences
    • Department of Physics and Astronomy & Department of Electrical Engineering and Computer Science, Vanderbilt University
    • Department of Physics and Astronomy and Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN
    • Department of Electrical Engineering and Computer Science, Vanderbilt University
    • Department of Physics and Astronomy and Department of Electrical Engineering and Computer Science, Vanderbilt University
    • Vanderbilt University