Role of Bi3+ substitution on structural, magnetic and optical properties of cobalt spinel ferrite

Bismuth-doped cobalt ferrite CoBixFe(2-x)O4 with x = 0, 0.1,0.2, 0.3, 0.4, 0.5 have been prepared using powder metallurgy route. The structural, morphological, elemental, magnetic and optical properties have been investigated using X-ray diffractometer, Fourier transform infrared spectroscopy, scanning electron microscope, energy dispersive X-rays, vibrating sample magnetometer and ultravioletvisible spectrometer, respectively. X-ray diffractometer analysis confirms the formation of single-phase cubic spinel structure. As the substitution of larger ionic radii Bi3+ ions increases in cobalt ferrite which is responsible to increase the lattice parameters and decrease the crystallite size. SEM micrographs revealed the spherical shape of the particles with the nonuniform grain boundaries. The saturation magnetization decreases and bandgap energy increases as the concentration of non-magnetic Bi3+ ions increases.