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

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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