Coordination number | An-Najah Staff

Local Environment of Indium in ‎Ge23.33Se64.67In12 Chalcogenide Glass

Wed, 2014-02-19 13:54 — Ghassan Saffarini

Journal Title, Volume, Page:

Materials Letters Volume 35, Issues 5–6 , Pages 309–313

Year of Publication:

1998

Link:

http://www.sciencedirect.com/science/article/pii/S0167577X97002711

Authors:

G. Saffarini

Physics Department, An-Najah National University, Nablus, Palestine

Current Affiliation:

Department of Physics, Faculty of Science, An-Najah National University, Palestine

[email protected]

J.M. Saiter

Laboratoire d'Etude et de Caracterisation des Amorphes et des Polymères, Faculté des Sciences, Université de Rouen, 76821 Mont Saint Aignan CEDEX, France

J. Ledru

Laboratoire d'Etude et de Caracterisation des Amorphes et des Polymères, Faculté des Sciences, Université de Rouen, 76821 Mont Saint Aignan CEDEX, France

S. Benazeth

LURE, Bâtiment 209d, Université de Paris-Sud, 91405 Orsay Cedex, France

Preferred Abstract (Original):

EXAFS measurements, from the In K edge, on Ge_23.33Se_64.67In₁₂ glass, have been performed. For this glass, it is found that In is only coordinated with Se atoms. By complementing the EXAFS results obtained from the fitting procedure followed in this work with the earlier reported DSC results obtained on this system, it is concluded that in this glass, the coordination number of In is equal to three. Moreover, this approach of coupling EXAFS with DSC results allows one to calibrate the Γ factor for systems which lack a reference material, or systems for which an ab initio calculation cannot be performed, as in our case.

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

Mon, 2011-03-07 12:42 — Ghassan Saffarini

Journal Title, Volume, Page:

Physica B: Condensed Matter, Volume 304, Issues 1-4, September 2001, Pages 228-236

Year of Publication:

2001

Link:

http://www.sciencedirect.com/science/article/pii/S0921452601005014

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

[email protected]

Preferred Abstract (Original):

The values of the thermal heat-capacity changes at the glass transition temperature T_g (ΔC_p=C_{p_l}−C_{p_g}) and the values of the apparent activation energy Δh* of the sub T_g relaxation process are determined for Ge_xTe_1−x (0.15 less-than-or-equals, slant x0.20) 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 Ge_xSe_1−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 Ge_xTe_1−x exhibits a kinetically fragile character which decreases as the amount of Ge increases in the alloy.