Colossal magnetodielectric effect in DyMn2O5: Electromagnons or rare earth?

ORAL

Abstract

We report on the results of spectroscopic studies of the excitations responsible for the colossal magnetodielectric effect in DyMn2O5 [1]. On one hand, many RMn2O5 compounds have electromagnons capable of inducing large steps in the dielectric constant. On the other hand, rare earth ions can posses electric dipole moments and also can produce dielectric anomalies. Both types of excitations are expected in the experimentally difficult low energy range 0.1-1 meV. We use high frequency dielectric, Fourier transform and back-wave oscillator spectroscopies in combination with low temperature and magnetic field up to 9 T to clarify the origin of the dielectric anomaly in DyMn2O5. [1] N. Hur, S. Park, P. A. Sharma, S. Guha, and S-W. Cheong, Colossal Magnetodielectric Effects in DyMn2O5, PRL 93, 107207 (2004).

*Work supported in part by NSF-MRSEC under grant DMR-0520471

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Authors

  • Andrei Sushkov

    • Department of Physics, University of Maryland, College Park, MD 20742
    • MRSEC and CNAM, Department of Physics, University of Maryland
    • Department of Physics, University of Maryland, College Park, MD 20742, USA
    • Center for Nanophysics and Advanced Materials, University of Maryland, College Park

  • Dennis Drew

    • MRSEC and CNAM, Department of Physics, University of Maryland

  • Christian Kant

    • ISSP, Vienna University of Technology, Austria

  • Alexey Shuvaev

    • ISSP, Vienna University of Technology, Austria

  • Andrei Pimenov

    • ISSP, Vienna University of Technology, Austria

  • Sergei Zvyagin

    • Dresden High Magnetic Field Laboratory, Germany

  • Bernd Lorenz

    • University of Houston

  • Sang-Wook Cheong

    • Rutgers University