Optical properties, lattice dynamics, and structural phase transition in polar magnets Fe<sub>2</sub>Mo<sub>3</sub>O<sub>8</sub> and Mn<sub>2</sub>Mo<sub>3</sub>O<sub>8</sub>

ORAL

Abstract

Optical properties and lattice dynamics of hexagonal M2Mo3O8 (M = Fe, Mn) single crystals are studied in a wide temperature range by means of infrared (IR) reflectivity and Raman scattering at the temperatures above and below the magnetic transitions. Experimental data for optical phonons are compared to group theoretical mode analysis and complimentary DFT and DMFT lattice dynamics calculations. At temperatures below TN(Fe)=60 K several additional IR- and Raman-active modes are detected in experimental spectra of Fe2Mo3O8. We also found several IR-active modes in the 2500 – 3500 cm-1 range in Fe2Mo3O8 at low temperatures. We attribute them to optical transitions from the ground state to the split levels of the 5T2 state of Fe2+ ions in the tetrahedral coordination.

*T.N.S., A.A.S., Y.W. and S.W.C. were supported by U.S. Department Energy DOE DE-FG02-07ER46382. Z.L., NSLS-II, BNL acknowledges DE-AC98-06CH10886 and CDAC DE-NA-0002006 support. A.P.L. was supported by the State of Texas via the Texas Center for Superconductivity.

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Presenters

  • Andrei Sirenko

    • New Jersey Institute of Technology

Authors

  • T.N. Stanislavchuk

    • New Jersey Institute of Technology

  • Andrei Sirenko

    • New Jersey Institute of Technology

  • A. P. Litvinchuk

    • Texas Center for Superconductivity, University of Houston

  • Zhenxian Liu

    • Brookhaven National Laboratory
    • C&EE Department, George Washington University
    • George Washington University
    • Brookhaven National Lab

  • Yazhong Wang

    • RCEM, Department of Physics and Astronomy, Rutgers U.

  • G.L. Lucian Pascut

    • Rutgers University, NJ, USA & “Stefan Cel Mare” University (USV), Suceava, Romania
    • RCEM, Department of Physics and Astronomy, Rutgers U.
    • Physics and Astronomy, Rutgers University, Piscataway, NJ, United States

  • Valery Kiryukhin

    • Rutgers University, New Brunswick
    • RCEM, Department of Physics and Astronomy, Rutgers U.

  • Sang-Wook Cheong

    • Rutgers University
    • Department of Physics and Astronomy, Rutgers University
    • Rutgers University, New Brunswick
    • Rutgers Center for Emergent Materials and Department of Physics & Astronomy, Rutgers University
    • Center for Quantum Materials Synthesis and Department of Physics and Astronomy, Rutgers, the State University of New Jersey
    • Department of Physics, Rutgers University
    • Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, NJ
    • Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854, USA
    • Physics, Rutgers University
    • Physics and Astronomy, Rutgers University, New Brunswick
    • Department of Physics and Astronomy, Rutgers University, New Jersey
    • Rutgers University, Physics and Astronomy, and Laboratory for Pohang Emergent Materials and Max Plank POSTECH Center for Complex Phase Materials, Pohang University of Science
    • RCEM, Department of Physics and Astronomy, Rutgers U.
    • Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University
    • Department of Physics and Astronomy, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, USA, Rutgers Center for Emergent Materials