Enhanced ferromagnetism of Er-doped BiFeO3 thin films derived from rhombohedral-to-orthorhombic phase transformations

The effects of Er doping on the crystal structure and ferromagnetism of BiFeO3 thin films were investigated. The magnetization of BiFeO3 thin films was enhanced in magnitude with increasing Er content. Thus enhanced ferromagnetism is attributed to the suppression of spin cycloid structure derived from the anabatic relative rotation of FeO6 octahedra belonging to R3c phase fraction in the process of rhombohedral-to-orthorhombic structural phase transformations. The present work provides a feasible method on enhancing the ferromagnetism of BiFeO3 thin films correlating with structural transformation.