Strong-Fragile Glass Forming Liquid Concept Applied To Gete Chalcogenide Glasses

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Journal Title, Volume, Page: 
Physica B: Condensed Matter, Volume 304, Issues 1-4, September 2001, Pages 228-236
Year of Publication: 
2001
Authors: 
K. Chebli
Laboratoire d’étude et de Caractérisation des amorphes et des polymères, Faculté des Sciences, Université de Rouen, 76821 Mont Saint Aignan Cedex, France
J.M. Saiter
Laboratoire d’étude et de Caractérisation des amorphes et des polymères, Faculté des Sciences, Université de Rouen, 76821 Mont Saint Aignan Cedex, France
J. Grenet
Laboratoire d’étude et de Caractérisation des amorphes et des polymères, Faculté des Sciences, Université de Rouen, 76821 Mont Saint Aignan Cedex, France
A. Hamou
Laboratoire d’étude des Matériaux Amorphes et des polymères, Faculté des Sciences, Université d’Oran, Es-sénia, Algeria
G. Saffarini
Department of Physics, Faculty of Sciences, An-Najah National University, Palestine
Current Affiliation: 
Department of Physics, Faculty of Sciences, An-Najah National University, Palestine
Preferred Abstract (Original): 

The values of the thermal heat-capacity changes at the glass transition temperature TgCp=CplCpg) and the values of the apparent activation energy Δh* of the sub Tg relaxation process are determined for GexTe1−x (0.15less-than-or-equals, slantxless-than-or-equals, slant0.20) vitreous alloys by means of differential scanning calorimetry investigations. The values of Δh* are then used to determine the values of the fragility index, m. The comparison of these new data to those already obtained on the GexSe1−x vitreous system leads to conclude that both systems exhibit strong thermodynamic character. The stronger thermodynamic character is reached at the Phillips–Thorpe's floppy-to-rigid transition. On the other hand, we find that GexTe1−x exhibits a kinetically fragile character which decreases as the amount of Ge increases in the alloy.

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