Evolution of spin wave excitations in Sr$_{2}$FeSi$_{2}$O$_{7}$ under an external magnetic field

ORAL

Abstract

Evolution of static and dynamic spin correlations in a new multiferroics material Sr$_{2}$FeSi$_{2}$O$_{7}$ under an external magnetic field was investigated by elastic and inelastic neutron scattering techniques. An external magnetic field up to $B$ = 14 Tesla induces four different magnetic and ferroelectric phases in Sr$_{2}$FeSi$_{2}$O$_{7}$. The static magneto-electric coupling can be understood as the spin-dependent metal-ligand hybridization proposed for a related material Ba$_{2}$CoGe$_{2}$O$_{7}$. By analyzing the inelastic neutron scattering data obtained from a single crystal of Sr$_{2}$FeSi$_{2}$O$_{7}$ without field, we have determined the effective spin Hamiltonian in this material that includes isotropic nearest neighbor exchange interaction in the two-dimensional Fe square plane and easy plane single ionic anisotropies. The spin wave excitations show interesting changes as upon ramping up the system enters the field-induced phases for $B \quad >$ 6.5 Tesla, which will also be discussed.

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Authors

  • Kazuki Iida

    • University of Virginia

  • Jooseop Lee

    • University of Virginia

  • Naoyuki Katayama

    • University of Virginia

  • Sungdae Ji

    • University of Virginia

  • Israel Klich

    • University of Virginia

  • Seunghun Lee

    • University of Virginia

  • Duc Le

    • Helmholtz Zentrum

  • Sung Chang

    • NIST Center for Neutron Research

  • Taehwan Jang

    • Pohang University of Science and Technology

  • Yoonhee Jeong

    • Pohang University of Science and Technology

  • S-W. Cheong

    • Rutgers Center for Emergent Materials
    • Rutgers University
    • Department of Physics and Astronomy and Rutgers Center for Emergent Materials, Rutgers University, Piscataway, New Jersey 08854, USA
    • Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
    • Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University
    • Rutgers Center for Emergent Materials and Dept of Phys and Astronomy, Rutgers U., NJ, USA
    • Department of Physics and Astronomy and Rutgers Center for emergent materials, Rutgers University, Piscataway, NJ 08854 USA