Physical ageing in Se-Te-Sb glasses

Vanitha, MK and Rao, Hanumantha MV and Asokan, S and Ramesh, K (2013) Physical ageing in Se-Te-Sb glasses. In: Journal of Physics and Chemistry of Solids, 74 (6). pp. 804-810.

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Abstract

Bulk Se60-xTe40Sbx glasses in the composition range 0 <= x <= 14 were prepared by the melt quenching method. Differential Scanning Calorimetric (DSC) and thermal crystallization studies were performed to understand the thermodynamic property like glass transition and structural transformations. These glasses exhibit sharp endothermic peak at the glass transition (T-g). Disappearance of the endothermic peak at T-g in the rejuvenated samples clearly indicates the ageing effect in these glasses. Addition of Sb to Se-Te increases the connectivity of the structural network which is evidenced from the increase in T-g. A distinct change in the slope of the T-g at x=6, indicates a major change in the way the network is connected. The glass forming ability and the thermal stability also exhibit a maximum at x=6. T-g increases with the ageing time and the corresponding fictive temperature (T-f) calculated from the specific heat curves shows a decreasing trend. The molecular movements along the polymeric Se chains might cause the structural relaxation and the physical ageing. The physical ageing effect has been understood on the basis of the Bond Free Solid Angle (BFSA) model proposed by Kastner. Thermally crystallized samples show the formation of rhombohedral Sb2Te3, rhombohedral Sb2Se3 and hexagonal Te phases.

Item Type:	Journal Article
Publication:	Journal of Physics and Chemistry of Solids
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Chalcogenides; Glasses; Differential Scanning Calorimetry (DSC); Specific Heat; Thermodynamic Properties
Department/Centre:	Division of Physical & Mathematical Sciences > Instrumentation Appiled Physics Division of Physical & Mathematical Sciences > Physics
Date Deposited:	28 May 2013 11:24
Last Modified:	28 May 2013 11:24
URI:	http://eprints.iisc.ac.in/id/eprint/46561

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