Far-IR spectra of magnons, crystal field transitions, and phonons in hexagonal \textit{RE}MnO$_{3}$ (\textit{RE}=Er, Tm, Yb, Lu) single crystals

ORAL

Abstract

Far-IR spectra of hexagonal \textit{RE}MnO$_{3}$ (\textit{RE}=Er, Tm, Yb, Lu) single crystals have been studied between $T$=1.6 K and 300 K using transmission in high magnetic field and rotating analyzer ellipsometry. The symmetry of the IR optical phonons and their oscillator strengths were determined for compounds with different \textit{RE} ions. The temperature dependence of the phonon frequencies revealed a strong spin-phonon interaction in the temperature range below $T_{N}\sim $70 K. The effective g-factors have been determined for the AFM resonances and crystal field transitions using external magnetic fields up to 10 T. The frequency of the AFM resonances around 50 cm$^{-1}$ increases systematically with a decrease of the \textit{RE} ion radius. The observed effects are analyzed taking into account main magnetic interactions in the system including exchange of the Mn$^{3+}$ spins with \textit{RE}$^{3+}$ paramagnetic moments. The magnetic ordering of \textit{RE} ions was observed at low temperatures $T<$3.5 K and in strong magnetic fields.

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Authors

  • E.C. Standard

    Dept of Phys, NJIT, Newark NJ, USA

  • T.N. Stanislavchuk

    Dept of Phys, NJIT, Newark NJ, USA

  • R. Basistyy

    Dept of Phys, NJIT, Newark NJ, USA

  • A.A. Sirenko

    Dept of Phys, NJIT, Newark NJ, USA

  • T.D. Kang

    ReCFI, Dept of Phys and Astronomy, Seoul National U., Seoul, Korea

  • Nara Lee

    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 University, 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

  • 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