Comparison of room-temperature multiferroics in Bi4Fe2TiO12 film and   bulk
  It is reported that both dielectricity and magnetism at room temperature have been appreciably improved in Bi4Fe2TiO12 film compared with that of Bi4Fe2TiO12 bulk. X-ray diffraction profiles reveal similar crystalline nature and random orientation of the two but X-ray photoelectron spectroscopy (XPS) experiments indicate 1.4 eV lower binding energy of core-state O 1s in film relative to those of bulk, so the improvement of multiferroics in film are attributed to the oxygen vacancies and high fraction of interface. The results have promising applications in multifunctional integrated devices. 
J. Lu, L.J. Qiao, W.Y. Chu