Joshi, Seema and Kumar, Manoj and Chhoker, Sandeep and Srivastava, Geetika and Jewariya, Mukesh and Singh, V. N. (2014) Structural, magnetic, dielectric and optical properties of nickel ferrite nanoparticles synthesized by co-precipitation method. Journal of Molecular Structure, 1076. 55-62 . ISSN 0022-2860

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Abstract

Nickel ferrite nanoparticles were synthesized by wet chemical co-precipitation method and the corresponding temperature dependent structural, magnetic and optical properties of these nanoparticles have been investigated. X-ray diffraction patterns show the single phase cubic spinal crystal structure belonging to the space group Fd3m. The average crystallite size varies in the range 8-20 nm with varying sintering temperature. Raman spectroscopy exhibits a doublet-like peak behaviour which indicates the presence of mixed spinel structure. The saturation magnetization, coercivity and remanence increase with increasing sintering temperature from 250 to 550 degrees C. The non-saturation and low values of magnetization at high fields indicate the strong surface effects to magnetization in NiFe2O4 nanoparticles. The g-value calculated from electron spin resonance spectrum indicates the transfer of divalent metallic ion from octahedral to tetrahedral site (i.e. mixed spinel structure). The dielectric permittivity, loss tangent and ac conductivity measurements show strong temperature dependence at all frequencies. The observed ac conductivity response suggests that the conduction in ferrite nanoparticles is due to feeble polaron hopping between Fe3+/Fe2+ ions. Room temperature UV vis diffuse spectra indicate that NiFe2O4 is an indirect band gap material with band gap ranges from 1.27 to 1.47 eV with varying sintering temperature. The photoluminescence study clearly indicates that the. Ni2+ ions occupy both octahedral and tetrahedral sites confirming mixed spinel structure.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/S Elsevier.
Uncontrolled Keywords:	Ferrites Crystal structure Optical properties Dielectric properties Magnetic properties
Subjects:	Chemistry
Divisions:	UNSPECIFIED
Depositing User:	Dr. Rajpal Walke
Date Deposited:	09 Nov 2015 11:06
Last Modified:	09 Nov 2015 11:06
URI:	http://npl.csircentral.net/id/eprint/1554

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