Structural, vibrational and dielectric study of Ni doped spinel Co ferrites: Co1−xNixFe2O4 (x=0.0, 0.5, 1.0)

Bulk samples of spinel ferrites with the compositional formula, Co1−xNixFe2O4 (x=0.0, 0.5, 1.0) were synthesized by a solid-state reaction route to discuss doping effect on the structural, vibrational and dielectric properties. The crystal structure and cell parameters were refined by the Rietveld analysis, infers that ceramics crystallized in single-phase cubic structure with Fd-3m space group. The variation in cell parameters with Ni substitution confirmed the partial substitution of the Co3+ by Ni3+ into the spinel CoFe2O4 structure. A blue shift in Ni doped CoFe2O4 ferrite has been observed as compared to parent CoFe2O4 from Raman scattering measurements. The dielectric constant (ε′) and loss tangent (tan δ) have been investigated as a function of composition and frequency in the frequency range 10 Hz-1 MHz. Porous ceramics are useful for microelectronics with lower value of dielectric constant.