Raman Evidence for Symmetry Breaking in SrCr$_{2}$O$_{4}$

ORAL

Abstract

Raman spectra from 400 cm$^{-1}$ to 650 cm$^{-1}$ were acquired from single crystalline SrCr$_{2}$O$_{4}$ to probe magneto-elastic effects on its frustrated magnetism. The compound contains two-dimensional sheets of CrO$_{2}$, where spin-3/2 Cr atoms with direct exchange interactions form a distorted triangular lattice with helical magnetic order below 43K [1]. Even in the paramagnetic phase, the spectra show mode splitting beyond predictions for space-group P$_{mmn}$ that describes powder x-ray diffraction data. This splitting occurs at the 480 cm$^{-1}$ A$_{g}$ mode and is enhanced below T$_{N}$, which suggests it may be associated with magneto-elastic effects. \\[4pt] [1] S E Dutton, E Climent-Pascual, P W Stephens, J P Hodges, A Huq, C L Broholm, and R J Cava, J. Phys.: Condens. Matter 23 (2011) 246005

*This work was supported by the U.S. Department of Energy, Office of Basic Energy Science, Division of Material Science and Engineering under Award DE-FG02-08ER46544.

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Authors

  • Michael Valentine

    • Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA

  • Si\^an Dutton

    • Department of Chemistry, Princeton University, Princeton, NJ 08544, USA

  • Seyed Koohpayeh

    • Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA

  • Robert Cava

    • Department of Chemistry, Princeton University
    • Dept. Chem. Princeton University, New Jersey 08544
    • Princeton University
    • Department of Chemistry, Princeton University, Princeton, NJ 08544, USA

  • Collin Broholm

    • Johns Hopkins University / NIST NCNR
    • Institute for Quantum Matter and Department of Physics and Astronomy, Johns Hopkins University
    • IQM, JHU; NCNR, NIST; Neutron Science Directorate, ORNL
    • Department of Physics and Astronomy, Johns Hopkins University, Baltimore 21218 MD USA
    • Johns Hopkins University
    • Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA

  • Turan Birol

    • School of Applied and Engineering Physics, Cornell University
    • Cornell University, Ithaca, New York 14853 USA

  • Hena Das

    • Cornell University
    • Cornell University, Ithaca, New York 14853 USA
    • School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA

  • Craig J. Fennie

    • School of Applied and Engineering Physics, Cornell University
    • Cornell University, Ithaca, New York 14853 USA
    • Scholl of Applied and Engineering Physics, Cornell University
    • School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853
    • Cornell University
    • School of Applied \& Engineering Physics, Cornell University

  • Natalia Drichko

    • Univ. J. Hopkins, Baltimore (U.S.A.)
    • Department of Physics and Astronomy, Johns Hopkins University, Baltimore 21218 MD USA
    • Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA