Impedance spectroscopic studies on microwave synthesized NaPO3-V2O5 glasses containing SO42- ions

Sujatha, B and Chethana, BK and Viswanatha, R and Nagabhushana, H (2015) Impedance spectroscopic studies on microwave synthesized NaPO3-V2O5 glasses containing SO42- ions. In: JOURNAL OF ALLOYS AND COMPOUNDS, 648 . pp. 622-628.

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Abstract

Impedance spectroscopic studies on modified phospho-vanadate glasses containing SO42- ions have been carried out over wide range of frequency. Modulated DSC studies suggest that the addition of alkali salt makes the glass less rigid and more fragile. The frequency dependent impedance data has been used to calculate d.c conductivity and activation energies. These values are comparable with the other ionic liquids. The conductivity and relaxation phenomenon was rationalized using universal a.c conductivity power law and modulus formalism. The activation energies for relaxation mechanism was also determined using imaginary parts of electrical modulus peaks which were close to those of the d.c conductivity implying the involvement of similar energy barriers in both the processes. Kohlrausch-William-Watts (KWW) stretched exponent beta, is temperature insensitive and power law (s) exponent is temperature dependent. The enhanced conductivity in these glasses is attributed to the depolymerised structure in which migration of Na+ ions proceeds in an expanded network comprising SO42- ions in the interstitials. The effect of structure on activation energy is well supported by abinitio DFT computations. (C) 2015 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	JOURNAL OF ALLOYS AND COMPOUNDS
Publisher:	ELSEVIER SCIENCE SA
Additional Information:	Copy right for this article belongs to the ELSEVIER SCIENCE SA, PO BOX 564, 1001 LAUSANNE, SWITZERLAND
Keywords:	Microwave method; Dynamic conductivity; Stretched exponent; Abinitio DFT
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	15 Oct 2015 05:32
Last Modified:	15 Oct 2015 05:32
URI:	http://eprints.iisc.ac.in/id/eprint/52537

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