Structure and Mossbauer study of nanocrystalline Ni-Zn ferrite

Ni1-xZnxFe2O4 (0.0 less than or equal to x less than or equal to 1.0) nanop articles have been prepared by the polyvinyl alcohol (PVA) sol-gel method. The lattice parameter of Ni-Zn ferrite nanoparticles is larger than that of the bulk material. The variation of saturation magnetization (M-s) as a fu nction of a: has been studied. The Mossbauer spectra of the samples at room temperature showed the presence of ultrafine particles, exhibiting superpa ramagnetic relaxation. At higher annealing temperature, the portion of the ferromagnetic ultrafine particles increased.