Dar, M. Abdullah and Majid , Kowsar and Najar , Mohd Hanief and Kotnala, R. K. and Shah , Jyoti and Dhawan, S. K. and Farukh, M. (2017) Surfactant-assisted synthesis of polythiophene/Ni0.5Zn0.5Fe2-xCexO4 ferrite composites: study of structural, dielectric and magnetic properties for EMI-shielding applications. Physical Chemistry Chemical Physics, 19 (16). pp. 10629-10643. ISSN 1463-9076

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Abstract

This work reports the exploitation of nanocrystalline Ni0.5Zn0.5Fe2-xCexO4 ferrite for potential application by designing quasi-spherical shaped polythiophene (PTH) composites via in situ emulsion polymerization. The structural, electronic, dielectric, magnetic, and electromagnetic interference (EMI) shielding properties of PTH/Ni0.5Zn0.5Fe2-xCexO4 composites were investigated. Our results suggest that these properties could be optimized by modulating the concentration of x (composition) in the polymer matrix. Higher values of epsilon' and epsilon '' were obtained on composite formation, and could be due to the heterogeneity developed in the material. An enhancement in the value of saturation magnetization (123 emu g(-1) for x = 0.04) and Curie temperature was obtained with Ce concentration, which is useful for high density recording purposes. A low value of saturation magnetization was obtained for the PTH/Ni0.5Zn0.5Fe2-xCexO4 composite (36 emu g(-1) for x = 0.04). This could be attributed to the nonmagnetic nature of the polymer. A total shielding effectiveness (SET = SEA + SER) up to 34 dB (E99.9% attenuation) was recorded for PTH/Ni0.5Zn0.5Fe2-xCexO4 composites (x = 0.04) in a frequency range of 8.2-12.4 GHz (X-band), which surpasses the shielding criteria of SET 4 30 dB for commercial purposes. Such a material with high SE identifies its potential for making electromagnetic shields. The effect of Ce substitution on the microstructure, dielectric, impedance and magnetic properties of PTH/Ni0.5Zn0.5Fe2-xCexO4 ferrite composites was also investigated. X-ray diffraction analysis confirmed cubic spinel phase formation, and the broad reflection peaks indicated the formation of smaller sized particles. The smaller energy band gap (2.53 eV) of the composite indicated that this material could be used for photocatalysis in the visible region. Dielectric and impedance measurements were carried out in a frequency range of 8.2-12.4 GHz. Dielectric properties were improved considerably by the substitution of Ce3+ ions in PTH/Ni0.5Zn0.5Fe2-xCexO4 composites. Impedance spectroscopy was used to study the effect of grain and grain boundaries on the electrical properties of PTH/Ni0.5Zn0.5Fe2-xCexO4 composites. Cole-Cole plots showed the formation of single semi-circles for all samples in the measured frequency range. This showed that the composite material was composed of good conducting grains and poorly conducting grain boundaries.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/S Royal Society of Chemistry.
Subjects:	Physics > Atomic and Molecular Physics Physical Chemistry/Chemical Physics
Divisions:	UNSPECIFIED
Depositing User:	Users 27 not found.
Date Deposited:	29 Apr 2019 07:34
Last Modified:	29 Apr 2019 07:34
URI:	http://npl.csircentral.net/id/eprint/2897

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