A composition dependent thermal behavior of GexSe35-xTe65 glasses

Prashanth, SB Bhanu and Asokan, S (2009) A composition dependent thermal behavior of GexSe35-xTe65 glasses. In: Journal Of Non-Crystalline Solids, 355 (22-23). pp. 1227-1230.

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Abstract

Alternating differential scanning calorimetric (ADSC) studies have been performed to understand the thermal behavior of bulk GexSe35-xTe65 glasses (17 <= x <= 25); it is found that the glasses with x <= 20 exhibit two crystallization exotherms (T-c1 & T-c2). On the other hand, those with x >= 20.5, show a single crystallization reaction upon heating. The exothermic reaction at T-c1 has been found to correspond to the partial crystallization of the glass into hexagonal Te and the reaction at T-c2 is associated with the additional crystallization of rhombohedral Ge-Te phase. The glass transition temperature of GexSe35-xTe65 glasses is found to show a linear but not-steep increase, indicating a progressive, but a gradual increase in network connectivity with Ge addition. It is also found that T-c1 of GexSe35-xTe65 glasses with x <= 20, increases progressively with Ge content and eventually merges with T-c2 at x approximate to 20.5 (< r > = 2.41); this behavior has been understood on the basis of the reduction in Te-Te bonds of lower energy and increase in Ge-Te bonds of higher energy, with increasing Ge content. Apart from the interesting composition dependent crystallization, an anomalous melting behavior is also exhibited by the GexSe35-xTe65 glasses.

Item Type:	Journal Article
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Chalcogenides;Calorimetry;Glass Transition.
Department/Centre:	Division of Physical & Mathematical Sciences > Instrumentation and Applied Physics (Formally ISU)
Date Deposited:	18 Aug 2009 05:09
Last Modified:	19 Sep 2010 05:41
URI:	http://eprints.iisc.ernet.in/id/eprint/22265

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