Electronic Resource
[S.l.]
:
American Institute of Physics (AIP)
Journal of Applied Physics
88 (2000), S. 2533-2540
ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The structural properties of As–Se–S glass system were investigated by x-ray absorption spectroscopy (XANES and EXAFS) using synchrotron radiation. A preliminary characterization by x-ray powder diffraction, differential scanning calorimetric and thermogravimetric measurements was also carried out. The changes in glass transition temperature (Tg) and glass decomposition temperature (Td) associated with glass compositions indicate that sulfur contributes to the instability of the ternary As–Se–S glass system. The XANES and EXAFS results suggest that arsenic is in trivalent state with approximately threefold coordination and selenium is in approximately twofold coordination in all the glass compositions under study. The homopolar bonding (As–As and Se–Se) has a significant contribution in AsSe1.42 glass matrix unlike in AsS1.56 glass where homopolar bonding (As–As) is negligible. However, the homopolar bonding (As–As) is increasingly eliminated with increasing replacement of selenium by sulfur in ternary glasses. In addition, the contribution of sulfur to the coordination of arsenic is more dominant than selenium even when glass matrices contain a larger quantity of selenium. Thus the present XANES and EXAFS results demonstrate that the As–Se–S glass system is well represented by the chemically ordered network model. © 2000 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1286109
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