Structural, magnetic and dielectric properties of Ni Co doped BiFeO3 multiferroics synthesized via micro-emulsion route

Abstract BiFe 1 -x Ni x Co x O 3 multiferroics (x = 0.00, 0.05, 0.1, 0.15 and 0.2) were fabricated by micro-emulsion process. Differential scanning calorimeter (DSC) plot exhibited broad exothermic peaks at 264.33 °C and 320.8 °C. X-ray diffraction (XRD) patterns indicated the rhombohedral phase with the R 3 c phase group. The crystallite size ranges from 48 to 11 nm. Bulk and X-ray densities were optimized by increasing cobalt and nickel concentration. Magnetic parameters such as retentivity (M r ), saturation magnetization (M s ) and coercivity (H c ) were studied for different compositions of BiFe 1- x Ni x Co x O 3 . BiFe 0.6 Ni 0.4 Co 0.4 O 3 behaves as ferromagnetic material having maximum saturation magnetization (10.6 emu/g) and maximum M r (5.2 emu/g). Enhanced magnetic properties were attributed to the difference in magnetic moment of doping element and Fe 3+ ions. Dielectric parameters had great influence of doping (Ni Co) in high frequency region. It was observed that by increasing doping level dielectric parameters were decreased appreciably.