Influence of transition elements doping on structural, optical and magnetic properties of BiFeO3 films fabricated by magnetron sputtering

Bi0.9La0.1Fe1-xCrxO3 (x=0.03, 0.05 and 0.07) thin films were deposited on LaNiO3/Si and quartz by RF magnetron sputtering, respectively. X-ray diffraction patterns indicate that all phases belong to BiFeO3, and no secondary phase is detected. Three A(1) modes and six E modes of the films are observed in Raman scattering spectra, and the A(1)-1 peak position shows red shift with the increasing of x, which indicates that the Cr doping induces more structural distortion. The band gap of the films for x=0.03, 0.05 and 0.07 can be expressed by (2.99-x) eV, which is due to the Cr doping that increases the tailing of conduction band edge into the band gap. With the Cr content increasing from 3% to 7%, the remnant magnetization and the magnetization at 10 kOe of the films show about 202% and 55% addition, respectively. (C) 2013 Elsevier B.V. All rights reserved.