Enhancement of magnetization in Eu doped BiFeO3 nanoparticles

Abstract

Bi 1 − x Eu x FeO 3 (BEFOx) nanoparticles have been synthesized by a sol-gel method. The samples maintain the pure rhombohedral structure up to x=0.1, while an impure phase of EuFeO3 is observed at x=0.15. The remenant magnetization of the BEFOx, which is significantly higher than those in nonmagnetically rare-earth doped BiFeO3, is found to increase with the increase of Eu concentration. Ferromagnetic coupling between Eu3+ and Fe3+ ions, evidenced by our first-principles calculations, is found to be the main reason for such a magnetization enhancement. In the mean time, the appearance of EuFeO3 phase is demonstrated to be another factor for the further magnetization enhancement in BEFOx=0.15.