Far-infrared transmission spectroscopy studies of HoMn$_{2}$O$_{5}$ single crystals at the commensurate-incommensurate phase transition

ORAL

Abstract

Spectra of the low-frequency IR-active excitations in HoMn$_{2}$O$_{5}$ multiferroic single crystals have been studied using synchrotron radiation based far-infrared transmission spectroscopy at U12IR beamline of NSLS-BNL in the frequency range between 8.5 and 105 cm$^{-1}$. Both preferable polarization of IR-active excitations along crystallographic directions of HoMn$_{2}$O$_{5}$ and temperature variation of their oscillator strength reveal strong changes at the commensurate-incommensurate phase transition at $T_{3 }$= 19 K. Transmission spectra are interpreted in terms of the electromagnon, magnon, and crystal-field splitting excitations.

*This work is supported by NSF (DMR 0546985); NSLS is supported by DOE (DE-AC02-98CH10886)

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Authors

  • A.A. Sirenko

    • Department of Physics, New Jersey Institute of Technology, Newark, NJ 07102

  • S. Park

    • Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854
    • Department of Physics, Rutgers University
    • Rutgers University

  • S. M. O' Malley

    • Department of Physics, New Jersey Institute of Technology, Newark, NJ 07102

  • G. L. Carr

    • Brookhaven National Laboratory
    • NSLS, Brookhaven National Laboratory, Upton, New York 11973

  • SangWook Cheong

    • Department of Physics \& Astronomy, Rutgers University, Piscataway, New Jersey 08854
    • Physics Department, Rutgers University
    • Rutgers University
    • Dept. of Physics and Astronomy, Rutgers University
    • Rutgers Center for Emergent Materials, Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854
    • Department of Physics, Rutgers
    • Rutgers Univ.