Excitation of electromagnons in the ferroelectromagnet TbMnO3 by an alternating electric field

The excitation of electromagnons in the ferroelectromagnetic phase of TbMnO3 by an electromagnetic wave is considered for different polarizations of the wave. in the case when the electric field of the wave is oriented perpendicular to the spontaneous polarization of the crystal, the results of calculations show that the frequency of the resonance absorption is independent of temperature, in agreement with experiment. When the electric field is directed along the spontaneous polarization it is predicted that the temperature and frequency dependence of the dielectric loss will have anomalies near the temperature of the ferroelectric transition. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3266915]