Anomalies of the phonon properties in multiferroic BiFeO3 thin films near the magnetic phase transition temperature

作者：Kovachev St; Wesselinowa J M^*

来源：Physics Letters A, 2010, 374(8): 1078-1082.

DOI：10.1016/j.physleta.2009.12.044

• Multiferroic thin films
• Phonon properties
• Anomaly near T-N
• Microscopic model

Size, Substrate, doping and magnetic field effects on the phonon properties in multiferroic BiFeO3 thin films are studied based on a microscopic model. We obtain an anomaly near the magnetic phase transition temperature T-N which can be attributed to the magnetoelectric nature of BiFeO3 and strong anharmonic spin-phonon interaction. It is shown that due to crystal lattice distortion for dopants with ionic radius smaller than that of the host ions the phonon energy decreases (for example Tb or Ti), whereas for the opposite case (larger radius of the doping ions, for example Co or Ni) it increases. The phonon damping is always enhanced compared to the undoped thin film.

• 出版日期2010-2-8