Electromagnons in multiferroic YMn2O5 and TbMn2O5

TL;DR

This study reports the detection of electromagnons in multiferroic YMn2O5 and TbMn2O5, linking them to dielectric anomalies and magneto-dielectric effects through temperature-dependent infrared spectra.

Contribution

It provides the first direct observation of electromagnons in these multiferroics and connects them to their dielectric and magneto-electric properties.

Findings

Electromagnons are responsible for dielectric anomalies.

Electromagnons contribute to colossal magneto-dielectric effects.

Temperature-dependent spectra reveal electromagnon behavior.

Abstract

Based on temperature dependent far infrared transmission spectra of YMn2O5 and TbMn2O5 single crystals, we report the observation of electric dipole-active magnetic excitations, or electromagnons, in these multiferroics. Electromagnons are found to be directly responsible for the step-like anomaly of the static dielectric constant at the commensurate--incommensurate magnetic transition and are the origin of the colossal magneto-dielectric effect reported in these multiferroics.