Nickel Spinel Ferrites: A review

FTIR study of Ni, Cu and Zn substituted nano-particles of MgFe2O4

A series of Sn4+ substituted NiFe2O4 with general formula Ni1−xSnxFe2O4 (x = 0.0, 0.2, 0.4, 0.6, and 0.8) has been prepared by novel combustion synthetic method. The prepared compounds have been sintered at 1000 °C and evaluated for their structural and electrical properties. XRD studies reveal the synthesized compounds are nanocrystalline size with cubic structure. The Fourier transform infrared (FT-IR) spectra show the characteristic features of the synthesized ferrite compounds. The UV–vis spectra reveal the optical band gap of the synthesized compounds. The dc electrical conductivity of the compounds found to increase with increasing measuring temperature. A maximum dc electrical conductivity of 6.0 S cm−1 was obtained at a measuring temperature of 1000 °C in the composition of x = 0.8, for which the activation energy for conduction is found to be minimum.

Combustion synthesis and characterization of Sn4+ substituted nanocrystalline NiFe2O4

Densification, magnetic and dielectric behaviour of Cu-substituted Mg–Zn ferrites

Influence of Al doping on electrical properties of Ni–Cd nano ferrites

The structural and electrical properties of magnesium-substituted nickel ferrite having the general formula of
Ni1xMgxFe2O4 (x=0, 0.3, 0.6, 0.9) has been studied as a function of magnesium ion concentration. The materials have
been prepared by citrate gel process using metal nitrate salts as a cation precursors and citric acid as gelating agent. The
powder X-ray diffraction pattern confirms fcc structure for the synthesized compound. The variation of lattice
parameter and the tetrahedral radius increases with increase in Mg2+ ion concentration. The AC electrical parameters
such as dielectric constant (e0) and loss tangent (tan d) for all the systems have been studied as a function of frequency in
the range 50 Hz to 10 kHz at room temperature. A maximum DC electrical conductivity of 3.3 S cm-1 was obtained at a
temperature of 1000C and a AC electrical conductivity of 10.94106at 10 kHz was observed in the composition
x ¼ 0:6 i.e. for Ni0.4Mg0.6Fe2O4 compound which may be due to the maximum Fe2+ concentration in the octahedral
sites. The dielectric constant follows the Maxwell’s–Wagner interfacial polarization and the relaxation peaks were
observed in the dielectric loss properties. The FTIR spectra show the characteristic peaks of ferrite sample. The
morphological features were studied using scanning electron microscope.

C.O. Augustin

Papers

Structural and electrical properties of Ni1xMgxFe2O4synthesized by citrate gel process