SEM micrographs of the samples
revealed that the grain size increases and the porosity decreases with the increase in sintering
temperature and has great influence on the magnetic properties of NiFe2O4 . Enhancement of real
part of initial permeability (µ′) as a function of frequency has been observed with the increase in
sintering temperature. Temperature dependence real part of initial permeability has been observed
at various sintering temperature and gives the manifestation of Hopkinson effect. Variation of Curie
temperature (Tc) has been found with the variation of sintering temperature.