Crystal Field Excitations in Raman Spectra of Pr-based Pyrochlores

ORAL

Abstract

Interplay of strong electron correlations and spin-orbit coupling leads to exotic magnetic phases in rare earth pyrochlores. Here we present a study of Pr2Ir2O7 and Pr2Zr2O7, which show magnetic interactions but no ordering down to low temperatures [1-3]. We performed low temperature Raman scattering spectroscopy study of Pr2Ir2O7 and Pr2Zr2O7 single crystals to probe crystal field excitations and phonons. A comparison of crystal field excitations in these two materials reveals a splitting in the Pr3+ crystal field doublet at 57 meV in Pr2Zr2O7, possibly originating from the magneto-elastic coupling induced vibronic state. An anomalous broadening of this crystal field excitation is observed in Pr2Ir2O7. A comparison of phonon spectrum to the density functional theory calculations demonstrates an anomalous broadening/splitting of the Eg phonon mode corresponding to the Ir-O-Ir (Zr-O-Zr) bending. We discuss relevance of our findings to magnetic properties of these materials.

[1] S. Nakatsuji, et al., Phys. Rev. Lett 96.8 (2006) 087204.
[2] Y. Machida, et al., Nature 463.7278 (2010) 210.
[3] K. Kimura et al., Nat. Commun. 4 (2013) 1934

*Supported by the Institute for Quantum Matter under DOE EFRC grant DE-SC0019331

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Presenters

  • Yuanyuan Xu

    • Department of Physics and Astronomy, Johns Hopkins University

Authors

  • Yuanyuan Xu

    • Department of Physics and Astronomy, Johns Hopkins University

  • Takumi Ohtsuki

    • The Institute for Solid State Physics, The University of Tokyo

  • Huiyuan Man

    • Stanford Univ
    • Department of Physics, Stanford University
    • Department of Physics and Astronomy, Johns Hopkins University

  • Nan Tang

    • Material Science Depeartment, University of Tennessee
    • The Institute for Solid State Physics, The University of Tokyo

  • Santu Baidya

    • Department of Physics and Astronomy, Piscataway, NJ 08854, Rutgers University
    • Department of Physics and Astronomy, Rutgers University

  • Hongbin Zhang

    • Technische Universitat Darmstadt
    • Institut für Materialwissenschaft, Technische Universität Darmstadt

  • Satoru Nakatsuji

    • Univ of Tokyo-Kashiwanoha
    • University of Tokyo
    • Institute for Solid State Physics, University of Tokyo
    • Institute for Solid State Physics, the University of Tokyo
    • Department of Physics, The University of Tokyo
    • Department of Physics, University of Tokyo
    • The Institute for Solid State Physics, The University of Tokyo
    • Institute for Solid State Physics, Univ of Tokyo-Kashiwanoha

  • David Vanderbilt

    • Department of Physics and Astronomy, Piscataway, NJ 08854, Rutgers University
    • Department of Physics and Astronomy, Rutgers University, New Brunswick, NJ, USA
    • Department of Physics & Astronomy, Rutgers University
    • Physics and Astronomy, Rutgers University
    • Department of Physics and Astronomy, Rutgers University
    • Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
    • Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, United States
    • Rutgers University
    • Physics, Rutgers University
    • Department of Physics and Astronomy, Rutgers University, New Brunswick
    • Rutgers University, New Brunswick

  • Natalia Drichko

    • Department of Physics and Astronomy, Johns Hopkins University