Evolution of spin wave excitations with Co-doping in the spinel MnV$_2$O$_4$

ORAL

Abstract

Spin waves were measured at several levels of Co-doping in the spinel system MnV$_2$O$_4$ by inelastic neutron scattering and analyzed with first-principles-guided spin models. Co-doping creates a rich phase diagram encompassing the transition from localized- to itinerant-electron regimes. Increasing Co concentration weakens the single-ion anisotropy and increases both the magnitude and isotropy of the nearest-neighbor exchange interactions. First principles calculations emphasize the the distinctly different microscopic origins of the two-in-two-out magnetic structure at the Mn-rich and Co-rich limits.

*Research at HFIR and SNS, ORNL, were sponsored by the Scientific User Facilities Division and Materials Science and Engineering Division, Office of Basic Energy Sciences, US Department of Energy.

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Authors

  • Steven Hahn

    • Neutron Data Analysis and Visualization Division, ORNL

  • J. Ma

    • Quantum Condensed Matter Division, ORNL
    • Oak Ridge National Laboratory
    • Quantum Condensed Matter Division, Oak Ridge National Laboratory
    • Oak Ridge Natl Lab, TN, USA

  • Jun Hee Lee

    • Materials Science and Technology Division, ORNL
    • Oak Ridge National Lab
    • Oak Ridge National Laboratory

  • Tao Hong

    • Quantum Condensed Matter Division, ORNL
    • Oak Ridge National Laboratory

  • Huibo Cao

    • Quantum Condensed Matter Division, ORNL

  • Adam Aczel

    • Quantum Condensed Matter Division, ORNL
    • Quantum Condensed Matter Division, ORNL, USA
    • QCMD, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory
    • Quantum Condensed Matter Division, Oak Ridge National Laboratory

  • Zhiling Dun

    • Department of Physics and Astronomy, University of Tennessee

  • Matthew Stone

    • Quantum Condensed Matter Division, ORNL
    • Oak Ridge National Laboratory
    • Quantum Condensed Matter Division, ORNL, USA
    • QCMD, Oak Ridge National Laboratory
    • Oak Ridge National Lab

  • W. Tian

    • Quantum Condensed Matter Division, ORNL
    • Quantum Condensed Matter Division, Oak Ridge National Laboratory
    • Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
    • Oak Ridge Natl Lab, TN, USA

  • Yiming Qiu

    • NIST Center for Neutron Research and Department of Materials Science and Engineering, University of Maryland

  • John Copley

    • NIST Center for Neutron Research

  • H.D. Zhou

    • Department of Physics and Astronomy, University of Tennessee
    • University of Tennessee
    • Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
    • Univ of Tennessee - Knoxville
    • U. of Tennessee
    • University of Tennessee Knoxville
    • University of Tennessee, TN, USA

  • Randy Fishman

    • Materials Science and Technology Division, ORNL
    • Oak Ridge National Laboratory

  • M. Matsuda

    • Quantum Condensed Matter Division, ORNL
    • Quantum Condensed Matter Division, Oak Ridge National Laboratory
    • Oak Ridge Natl Lab, TN, USA