Magnetic order and electromagnon excitations in DyMnO3 studied by neutron scattering experiments

TL;DR

This study uses neutron scattering to explore magnetic order and electromagnon excitations in DyMnO3, revealing complex magnetic interactions and identifying electromagnon modes linked to multiferroic behavior.

Contribution

It provides detailed neutron scattering data on DyMnO3, highlighting the interplay between Mn and Dy magnetism and identifying electromagnon excitations related to the multiferroic phase.

Findings

Mn magnetic order exhibits hysteresis due to Mn-Dy interplay

Magnon dispersion similar to TbMnO3

Identification of electromagnon modes at zone center and boundary

Abstract

Magnetic order and excitations in multiferroic DyMnO3 were studied by neutron scattering experiments using a single crystal prepared with enriched 162Dy isotope. The ordering of Mn moments exhibits pronounced hysteresis arising from the interplay between Mn and Dy magnetism which possesses a strong impact on the ferroelectric polarization. The magnon dispersion resembles that reported for TbMnO3. We identify the excitations at the magnetic zone center and near the zone boundary in the b direction, which can possess electromagnon character. The lowest frequency of the zone-center magnons is in good agreement with a signal in a recent optical measurement so that this mode can be identified as the electromagnon coupled by the same Dzyaloshinski-Moriya interaction as the static multiferroic phase.