Excitations and long-range-order in a crystalline ferromagnetic semiconductor

ORAL

Abstract

We present polarized and unpolarized neutron diffraction measurements as well as inelastic neutron scattering measurements examining the dilute ferromagnetic semiconductor Yb$_{14}$MnSb$_{11}$. We find that the system consists of RKKY ferromagnetic exchange coupled Mn$^{2+}$ sites with nearest and next nearest neighbor exchange interactions dominating the magnetic spectrum. We observe a distribution of negative magnetization density throughout the crystal structure with no significant negative magnetization on any single site. The extended spread of a negative magnetization around each of the Mn ions supports a Kondo screening cloud scenario for Yb$_{14}$MnSb$_{11}$.

*A portion of this research at ORNL's High Flux Isotope Reactor and Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy.

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Authors

  • Matthew Stone

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

  • vasile Garlea

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

  • Beatrice Gillon

    • Laboratoire Leon Brillouin

  • Alain Cousson

    • Laboratoire Leon Brillouin

  • Andrew Christianson

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

  • Mark Lumsden

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

  • Stephen Nagler

    • Quantum Condensed Matter Division, Oak Ridge National Laboratory

  • David Mandrus

    • The University of Tennessee, Knoxville
    • Department of Materials Science and Engineering, University of Tennessee, Knoxville, Knoxville, Tennessee 37996, USA
    • Oak Ridge National Laboratory \& University of Tennessee
    • University of Tennessee, Knoxville
    • Department of Materials Science and Engineering, University of Tennessee

  • Brian Sales

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