Cation Distribution, Magnetic and Hyperfine Interaction Studies of Superparamagnetic Ni-Zn Spinel Ferrites: Role of Jahn Teller ion (Cu2+) Substitution

The work reports cation distribution, magnetic and hyperfine interaction studies of Cu2+ substituted mixed Ni-Zn nanospinel ferrites prepared by combustion technique. X-ray diffraction and electron microscopy were used to study the structural and morphological aspects of all the samples. The Rietveld refined diffraction patterns exhibited cubic-spinel lattice structure with Fd-3m space-group for all the samples. The morphology investigations revealed the spherical morphology of particles with some agglomeration. Magnetic properties performed at 300K and 5K showed the soft ferromagnetic character of all the samples. Magnetization at 5K was progressively enhanced due to the surface effects. Field cooled and zero field cooled measurements were indicated net irreversibility for all the samples. The hyperfine interaction studies revealed the superparamagnetic nature of Cu2+ substituted mixed Ni-Zn spinel nano-ferrites. All the obtained results show that prepared nanoparticles are useful for magnetic fluid hyperthermia and other bio-applications.