Structural and lithium ion transport studies in sol-gel-prepared lithium silicophosphate glasses

Rao, KJ and Baskaran, N and Ramakrishnan, PA and Ravi, BG and Karthikeyan, A (1998) Structural and lithium ion transport studies in sol-gel-prepared lithium silicophosphate glasses. In: Chemistry of Materials, 10 (10). pp. 3109-3123.

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Abstract

Lithium silicophosphate glasses have been prepared by a sol-gel route over a wide range of compositions. Their structural and electrical properties have been investigated. Infrared spectroscopic studies show the presence of hydroxyl groups attached to Si and P. MAS NMR investigations provide evidence for the presence of different phosphatic units in the structure. The variations of de conductivities at 423 K and activation energies have been studied as a function of composition, and both exhibit an increasing trend with the ratio of nonbridging oxygen to bridging oxygen in the structure. Ac conductivity behavior shows that the power law exponent, s, is temperature dependent and exhibits a minimum. Relaxation behavior has been examined in detail using an electrical modulus formalism, and modulus data were fitted to Kohlraush-William-Watts stretched exponential function. A structural model has been proposed and the unusual properties exhibited by this unique system of glasses have been rationalized using this model. Ion transport in these glasses appears to be confined to unidimensional conduits defined by modified phosphate chains and interspersed with unmodified silica units.

Item Type:	Journal Article
Publication:	Chemistry of Materials
Publisher:	American Chemical Society
Additional Information:	Copyright of this article belongs to American Chemical Society.
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	31 Dec 2009 06:31
Last Modified:	19 Sep 2010 05:27
URI:	http://eprints.iisc.ac.in/id/eprint/19303

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