Conductivity studies on microwave synthesized glasses

Rajiv, Asha and Reddy, Sudhakara M and Viswanatha, R and Uchil, Jayagopal and Reddy, Narayana C (2015) Conductivity studies on microwave synthesized glasses. In: BULLETIN OF MATERIALS SCIENCE, 38 (4). pp. 985-993.

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Abstract

Conductivity measurements have been made on x V O-2(5) - (100-x) 0.5 Na2O + 0.5 B2O3] (where 10 a parts per thousand currency sign x a parts per thousand currency sign 50) glasses prepared by using microwave method. DC conductivity (sigma) measurements exhibit temperature-and compositional-dependent trends. It has been found that conductivity in these glasses changes from the predominantly `ionic' to predominantly `electronic' depending upon the chemical composition. The dc conductivity passes through a deep minimum, which is attributed to network disruption. Also, this nonlinear variation in sigma (dc) and activation energy can be interpreted using ion-polaron correlation effect. Electron paramagnetic resonance (EPR) and impedance spectroscopic techniques have been used to elucidate the nature of conduction mechanism. The EPR spectra reveals, in least modified (25 Na2O mol%) glasses, conduction is due to the transfer of electrons via aliovalent vanadium sites, while in highly modified (45 Na2O mol%) glasses Na+ ion transport dominates the electrical conduction. For highly modified glasses, frequency-dependent conductivity has been analysed using electrical modulus formalism and the observations have been discussed.

Item Type:	Journal Article
Publication:	BULLETIN OF MATERIALS SCIENCE
Publisher:	INDIAN ACAD SCIENCES
Additional Information:	Copy right for this article belongs to the INDIAN ACAD SCIENCES, C V RAMAN AVENUE, SADASHIVANAGAR, P B #8005, BANGALORE 560 080, INDIA
Keywords:	Conductivity; electrical modulus; impedance; microwave; power law; stretched exponent
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	24 Sep 2015 05:38
Last Modified:	24 Sep 2015 05:38
URI:	http://eprints.iisc.ac.in/id/eprint/52454

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