Thermally reversing window in Ge15Te85-xInx glasses: Nanoindentation and micro-Raman studies

Varma, Sreevidya G and Kiran, MSRN and Muthu, DVS and Ramamurty, U and Sood, AK and Asokan, S (2012) Thermally reversing window in Ge15Te85-xInx glasses: Nanoindentation and micro-Raman studies. In: JOURNAL OF NON-CRYSTALLINE SOLIDS, 358 (23). pp. 3103-3108.

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Abstract

Nanoindentation studies on Ge15Te85-xInx glasses indicate that the hardness and elastic modulus of these glasses increase with indium concentration. While a pronounced plateau is seen in the elastic modulus in the composition range 3 <= x <= 7, the hardness exhibits a change in slope at compositions x = 3 and x = 7. Also, the density exhibits a broad maximum in this composition range. The observed changes in the mechanical properties and density are clearly associated with the thermally reversing window in Ge15Te85-xInx glasses in the composition range 3 <= x <= 7. In addition, a local minimum is seen in density and hardness around x = 9, the chemical threshold of the system. Further, micro-Raman studies reveal that as-quenched Ge15Te85-xInx samples exhibit two prominent peaks, at 123 cm(-1) and 155 cm(-1). In thermally annealed samples, the peaks at 120 cm(-1) and 140 cm(-1), which are due to crystalline Te, emerge as the strongest peaks. The Raman spectra of polished samples are similar to those of annealed samples, with strong peaks at 123 cm(-1) and 141 cm(-1). The spectra of lightly polished samples outside the thermally reversing window resemble those of thermally annealed samples; however, the spectra of glasses with compositions in the thermally reversing window resemble those of as-quenched samples. This observation confirms the earlier idea that compositions in the thermally reversing window are non-aging and are more stable. (C) 2012 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	JOURNAL OF NON-CRYSTALLINE SOLIDS
Publisher:	ELSEVIER SCIENCE BV
Additional Information:	Copyright for this article belongs to ELSEVIER SCIENCE BV, NETHERLANDS
Keywords:	Chalcogenide glasses;Thermally reversing window;Nanoindentation;Micro-Raman spectroscopy
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy) Division of Physical & Mathematical Sciences > Instrumentation Appiled Physics Division of Physical & Mathematical Sciences > Physics
Date Deposited:	29 Jan 2013 12:31
Last Modified:	29 Jan 2013 12:31
URI:	http://eprints.iisc.ac.in/id/eprint/45701

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