Extended rigidity percolation and chemical thresholds in Ge–Te–Pb glasses as revealed by MDSC

Saheb, Zaheerudeen P and Sharmila, BH and Asokan, S and Gowda, Appaji K (2004) Extended rigidity percolation and chemical thresholds in Ge–Te–Pb glasses as revealed by MDSC. In: Solid State Communications, 129 (12). pp. 765-768.

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Abstract

Thermal analysis of $Ge_{20}Te_{80-x}Pb_x$ $(2 \leq x \leq 8)$ glasses has been undertaken using modulated differential scanning calorimetry (MDSC). The compositional dependence of thermal parameters is investigated. The crystallization temperatures $(T_c)$ estimated from the total heat flow show detectable changes at compositions x = 4,6.5 and 7.5. Further, the heat capacity change at the glass transition temperature, measured from the reversible heat flow curve $(\triangle {C}^R _p ),$ is found to exhibit a maximum and an inflexion at compositions x = 4 and 6.5 and minimum at x = 7:5, respectively. Also, the relaxation enthalpy, estimated from the area under the non-reversing heat flow curve $({\triangle}H^{NR}),$ exhibits similar features at the said compositions. From the observed MDSC results, it has been proposed that the compositions x = 4 and x = 6.5 denote to the onset and completion of rigidity percolation and x = 7:5 corresponds to the chemical threshold of the system.

Item Type:	Journal Article
Publication:	Solid State Communications
Publisher:	Elsevier
Additional Information:	The copyright belongs to Elsevier.
Keywords:	A.Disordered systems;D.Heat capacity;D.Thermodynamic properties
Department/Centre:	Division of Physical & Mathematical Sciences > Instrumentation Appiled Physics
Date Deposited:	27 May 2006
Last Modified:	19 Sep 2010 04:27
URI:	http://eprints.iisc.ac.in/id/eprint/6994

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