Quantum-Spin-Liquid Corrections near a Transition to Strong Ferromagnetism

ORAL

Abstract

The Curie temperature of bulk and nanostructured Fe5Si3 is investigated using experiments, density-functional simulations, and many-body model calculations. The bulk intermetallic, which crystallizes in the hexagonal D88 structure, exhibits several intriguing features: it does not exist as a room-temperature equilibrium phase, is close to the onset of ferromagnetism, and exhibits two crystallographically very different Fe sites. The samples, produced by rapid quenching (bulk) and cluster deposition (nanoparticulate thin films), have Curie temperatures of about 400 K, with a pronounced dependence on the Si content. Calculations using the Vienna ab-initio simulation package (VASP) show that the nanostructuring triggers a transition from weak to strong ferromagnetism. Interatomic exchange constants are calculated using the Kohn-Korringa-Rostoker (KKR) method and used to solve the multisublattice mean-field problem for the system, VASP calculations are used to study the dependence of the Fe moment on the thermally induced spin misalignment, and a model calculation yields an estimate for quantum-spin-liquid corrections.

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Presenters

  • Ralph Skomski

    Nebraska Center for Materials and Nanoscience and Department of Physics and Astronomy, Univ of Nebraska - Lincoln, University of Nebraska, Physics and Astronomy, University of Nebraska

Authors

  • Ralph Skomski

    Nebraska Center for Materials and Nanoscience and Department of Physics and Astronomy, Univ of Nebraska - Lincoln, University of Nebraska, Physics and Astronomy, University of Nebraska

  • Pankaj Kumar

    University of Nebraska

  • Balamurugan Balasubramanian

    Nebraska Center for Materials and Nanoscience and Department of Physics and Astronomy, Univ of Nebraska - Lincoln, University of Nebraska

  • Bhaskar Das

    University of Nebraska

  • Priyanka Manchanda

    Department of Physics and Astronomy, Vanderbilt University, Physics, Vanderbilt, Vanderbilt Univ

  • Arti Kashyap

    IIT Mandi

  • David Sellmyer

    University of Nebraska, Nebraska Center for Materials and Nanoscience and Department of Physics and Astronomy, Univ of Nebraska - Lincoln, Physics and Astronomy, University of Nebraska