Magnetic order and electromagnon excitations in DyMnO3 studied by   neutron scattering experiments
  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. 
T. Finger, K. Binder, Y. Sidis, A. Maljuk, D. N. Argyriou, and M.   Braden
cond-mat.str-el