Structural, optical and dielectric properties of transition metal (MFe2O4; M = Co, Ni and Zn) nanoferrites

Structural, optical and dielectric properties of transition metal (MFe2O4; M = Co, Ni and Zn) nanoferrites

In the present work, transition metal spinel ferrite (MFe2O4; M = Co, Ni, Zn) nanostructures synthesized by chemical co-precipitation method. XRD analysis confirms the formation of cubic spinel-type structure with space group Fd3m and the average crystallite size calculated by Scherrer's formul...

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Bibliographic Details
Published in:Physica. B, Condensed matter Vol. 524; pp. 53 - 63
Main Authors: Chand, Prakash, Vaish, Swapnil, Kumar, Praveen
Format: Journal Article
Language:English
Published: Amsterdam Elsevier B.V 01-11-2017
Elsevier BV
Subjects:
Absorption spectra
Banded structure
Chemical precipitation
Chemical synthesis
Cobalt ferrites
Dielectric properties
Electron microscopy
Energy gap
Ferrites
Frequencies
Grain boundaries
Impedance spectroscopy and dielectric properties
Mathematical analysis
Metals
Nanoparticles
Nickel ferrites
Optical properties
Raman spectra
Scanning electron microscopy
Spinel
Spinel ferrites
Zinc ferrites
Nanoparticles
Impedance spectroscopy and dielectric properties
Optical properties
Spinel ferrites
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Summary:In the present work, transition metal spinel ferrite (MFe2O4; M = Co, Ni, Zn) nanostructures synthesized by chemical co-precipitation method. XRD analysis confirms the formation of cubic spinel-type structure with space group Fd3m and the average crystallite size calculated by Scherrer's formula found to be in 9–14nm range. Scanning electron microscopy was used to study surface morphology of the samples. Moreover, Raman and PL spectra also confirm the formation of the cubic structure. The Raman spectra measured on cobalt, nickel and zinc ferrite revealed a larger number of phonon bands than expected for the cubic spinel structure. The calculated optical energy band gaps, obtained by Tauc's relation from UV–Vis absorption spectra are found to be as 2.44, 3.54 and 3.25eV for CoFe2O4, NiFe2O4&ZnFe2O, respectively. The analysis of the complex impedance spectra of all ferrites samples shows the presence of one semicircular arc at all selected temperatures, signifying a key role of the grain boundary contribution. The dielectric constants (ε′) were measured in the frequency range from 10Hz to 5MHz at different temperatures and is found to be decreased suddenly with an increase in frequency and maintain a steady state or constant at higher frequencies for all the three samples. The AC conductivity is found to be increased with frequency and temperature of all the three samples which is explained on the basis of Koop's phenomenological theory.
ISSN:0921-4526
1873-2135
DOI:10.1016/j.physb.2017.08.060