Ultrasonic velocities and thermal expansion coefficients of amorphous Se80Te20 and Se90Te10 alloys near glass transitions

Lakshmikumar, ST and Padaki, VC and Krishnapur, PP and Subramanyam, SV and Mallya, RM and Gopal, ESR (1982) Ultrasonic velocities and thermal expansion coefficients of amorphous Se80Te20 and Se90Te10 alloys near glass transitions. In: Journal of Materials Science, 17 (1). pp. 183-192.

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Abstract

Precise measurements of the ultrasonic velocities and thermal expansivities of amorphous Se80Te20 and Se90Te10 alloys are reported near the glass transition. The samples are produced by liquid quenching. The longitudinal and transverse velocities are measured at 10 MHz frequency using the McSkimin pulse superposition technique. The thermal expansivities,agr, are measured using a three-terminal capacitance bridge. Theagr-values show a sharp maximum near the glass transition temperature,T g. The ultrasonic velocities also show a large temperature derivative, dV/dT nearT g. The data are discussed in terms of existing theories of the glass transition. The continuous change inagr shows that the glass transition is not a first-order transition, as suggested by some theories. The samples are found to be deformed by small loads nearT g. The ultrasonic velocities and dV/dT have contributions arising from this deformation.

Item Type:	Journal Article
Publication:	Journal of Materials Science
Publisher:	Springer
Additional Information:	Copyright of this article belongs to Springer.
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	24 Dec 2009 12:01
Last Modified:	19 Sep 2010 05:43
URI:	http://eprints.iisc.ac.in/id/eprint/22694

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