Sc modified multiferroic BiFeO3 thin films prepared through a sol-gel process

Multiferroic thin films with the general formula BiFe1-xScxO3 (x=0.0, 0.1, 0.3, and 0.5 mol %) (BFS) were synthesized on Pt/Ti/SiO2/Si substrates through a sol-gel deposition method. From the x-ray diffraction (XRD) analysis, it was observed that the unit cell volume increased upon Sc doping up to 0.3 mol %. Impure phase appeared for the BFS (Sc: 0.5 mol %) films. Leakage current, ferroelectric, and magnetic properties were also found to improve for Sc doping up to 0.3 mol %. Room temperature magnetic coercive field for in-plane orientation of films showed the lowest value for BFS (Sc: 0.3 mol %) films, which indicates that BFS (Sc: 0.3 mol %) films were more magnetically soft. Room temperature value of the magnetodielectric effect in the presence of magnetic field of 8 kOe was found to have maximum of 3.36% for the BFS (Sc: 0.3 mol %) films. From the x-ray photoelectron spectroscopy measurements, it was observed that the Fe has mixed valency states of 2+ and 3+. The ratio of Fe2+ and Fe3+ was found to decrease slightly in BFS (Sc: 0.3 mol %) films. The improved leakage current and M-H loops support the authors' observation. (c) 2007 American Institute of Physics.