Structural, optical and magnetic modulation in Mn and Mg co-doped BiFeO3 films grown on Si substrates

Slightly Mn and Mg co-doped BiFeO3 films (BiFeO3, BiFe0.95Mg0.01Mn0.04O3, BiFe0.94Mg0.02Mn0.04O3 and BiFe0.93Mg0.03Mn0.04O3, xBFMMO, x = 0, 0.01, 0.02 and 0.03) have been grown on Si (1 0 0) substrates by sol-gel technique. Rhombohedral lattice structure and phase transition is confirmed by X-ray diffraction and Raman spectroscopy. The improved surface morphology and decreased grain size of films can be observed in SEM micrographs due to the influence of Mn and Mg co-doping. Blue emissions of xBFMMO films can be found in Photoluminescence spectra, meanwhile the nonlinear shift of emission peaks imply the variation of bandgap. Room-temperature magnetization versus magnetic field (M-H) curves exhibit enhanced saturation magnetization compared with parental BiFeO3, which can attribute to destroyed spin cycloid and released locked magnetization. These properties offer a great potential on the multiferroic information storage application.