Microwave dielectric constant measurements of multiferroic TbMn$_{2}$O$_{5}$

ORAL

Abstract

We have measured the temperature dependence of the dielectric constant of TbMn$_{2}$O$_{5}$ by a cavity perturbation technique at frequencies between 2 and 13 GHz. There are three anomalous features seen in the quasistatic dielectric constant as a function of termperature below the onset of magnetic ordering ($\sim $ 38 K); however at microwave frequencies, the enhancement in the dielectric constant is significantly reduced. In fact, by 13 GHz, the anomalies have nearly disappeared. Each anomaly has its own characteristic relaxation frequency, with the ones at higher and lower temperature being in the GHz range and the intermediate one being in the MHz. We discuss these results in terms of magnetoelectric domains.

*This work was supported in part by NSF Grant DMR-0520471.

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Authors

  • Samuel Lofland

    • Rowan Univ.
    • Rowan University

  • A Sushkov

    • Materials Research Science and Engineering Center, University of Maryland
    • University of Maryland

  • H.D. Drew

    • Physics Dept., Univ. of Maryland, College Park, MD
    • Department of Physics, University of Maryland, College Park, Maryland 20742, USA
    • Physics Department, University of Maryland, College Park, MD 20742
    • University of Maryland, College Park, MD 20742
    • Department of Physics, University of Maryland, College Park, Maryland 20742 USA
    • University of Maryland

  • Sang-Wook Cheong

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