Structural, electrical and dielectric properties of spinel nickel ferrite prepared by soft mechanochemical synthesis

Nickel ferrite, NiFe2O4 was prepared by a soft mechanochemical route from a mixture of (1) Ni(OH)2 and α-Fe2O3 and (2) Ni(OH)2 and Fe(OH)3 powders in a planetary ball mill for 25 h. The powder samples were sintered at 1100 °C for 2 h and were characterized by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). Impedance spectroscopy techniques were used to study the effect of grain and grain boundary on the electrical properties of the prepared samples. A difference in dielectric constant (ɛ) and dielectric loss tangent (tan δ) of NiFe2O4 samples obtained by the same methods but starting from different initial components was observed.