We observed “one magnon,” scattering in multiferroicpolycrystalline Bi Fe O 3 thin films near 17.2 cm − 1 at 90 K employing Raman spectroscopy. It is seen with a kink in magnon intensity at 150 K and with strong anomaly near 210 K illustrating spin reorientation transition. The spectral weight of one magnon transferred to the lowest phonon mode near the spin reorientation temperature suggests magnon-phonon coupling. Dielectric constant and dielectric loss as function of temperature showed anomaly at 210 K suggesting magnon-phonon-electric dipole coupling. The one magnon becomes overdamped or overcome by elastic scattering at elevated temperatures.
Kumar, A., Murari, N. M., & Katiyar, R. S. (2008). Observation of one magnon and magnon-phonon-electric dipole coupling in multiferroics bismuth ferrite thin films. Applied Physics Letters, 92(15). https://doi.org/10.1063/1.2911732