Synthesis of Bi3+ substituted Ni-Cu ferrites and study of structural, electrical and magnetic properties

Bi3+ substituted Ni-Cu ferrites with the particles size 0.28 μm-0.53 μm were prepared by solid state reaction method. X-ray diffraction analysis confirmed the single phase cubic spinel structure with the space group of Fd3m-Oh7. IR absorption bands assigned at 580 cm−1 and 403 cm−1 corresponds to the stretching of vibrations of tetrahedral and octahedral complexes of the ferrites. The average grain sizes of the ferrites were estimated by SEM micrographs at around 1.04 μm which was found to be increased with Bi content. The decrease of DC resistivity as a function of temperature shows the semiconducting nature of ferrites and is attributed to the increase in thermally activated drift mobility of charge carriers. The dielectric constant decreases with increase in the frequency of all samples shows dispersion behavior. Hysteresis loop of the ferrites at room temperature were studied for the determination of saturation magnetization and magnetic moment. The maximum saturation magnetization obtained is about 41.27emu/gm for Ni0.5Cu0.5Fe2O4 ferrite.