Abstract:
Hydrazinated nickel cobalt zinc ferrous fumarate precursor has been synthesized and decomposed autocatalytically to Ni(0.4)Co(0.2)Zn(0.4)Fe(2)O(4). The thermal decomposition behavior of the precursor has been investigated by thermogravimetric (TG) and differential thermal analysis (DTA). The chemical composition was assigned to precursor based on chemical analysis, TG-DTA, infrared (IR), isothermal mass loss, and total mass loss studies. The X-ray powder diffraction of the decomposed precursor confirms the formation of monophasic nickel cobalt zinc ferrite, and IR spectrum exhibits two peaks in the region of 340-420 and 550-660 cm sup(-1) characteristic of spinel ferrites. The average grain size evaluated by TEM is found to be 15-20 nm. The electrical DC resistivity measurement was carried out with respect to temperature using two-probe method and dielectric properties as a function of frequency. The high dielectric constant values found at lower frequencies were due to nanosize nature of the "as prepared" ferrite. The Curie temperature of the "as-prepared" Ni(0.4)Co(0.2)Zn(0.4)Fe(2)O(4) determined by alternating current susceptibility measurements was found to be 380 degrees C.
