Technique used to determine it.
Please provide recent references.
Hi Ghassan,
by XANES / NEAXFS spectroscopy you are able to obtain the oxidation state of a specific atom, which is adressable by its K-, or L-edge energy.
Fortunately here on RG there is a paper available (per full text request) dealing with Sb in chalcogenide glasses. Please see the link. The paper may help you.
Article XANES studies of unoccupied electronic states and local real...
The following article will be useful to answer your question: Journal of Ovonic Research Vol. 1, No. 1, February 2005, p. 1 – 6
In the case of the glassy system, GexSby Te1-x-y , the Ge, Sb and Te atoms are probably 4 ,3 and 2 fold coordinated, respectively. Recent x-ray absorption fine structure (EXAFS) experiment[1] tend to confirm these suggestions. The average coordination number for all glasses in the system can be calculated in exact analogy with the Ge-As-Se ternary system [2,3]. For simplicity you can consider the normalized composition, GexSbyTe1-x-y where x and y are between zero and one.
In this case the average coordination number of all three elements, nav , is
nav = 4x + 3y + 2(1 - x - y) = 2x + y + 2
[1] A. V. Kolobov, P. Fons, A. I. Frenkel, A. L. Ankudinov, J. Tominaga, T. Uruga,
Nature Materials, (2004) [on-line].
[2] P. Boolchand, D. G. Georgiev, T. Qu, F. Wang, L. Cai, S. Chakravarty, C. R. Chimie
5,713 (2002).
[3] P. C. Taylor, Z. M. Saleh, and J. Z. Liu, in Transport, Correlation and Structural Defects, H. Fritzsche, ed. (World Scientific, Singapore, 1990), p. 3.
Dear Dr. Ghassan Saffarini
Peace be upon you
In materials science the coordination number of a central atom in a molecule is the number of its near neighbors. This number is determined somewhat differently for molecules. On the other hand, antimony compounds are often classified according to their oxidation state: Sb(III) and Sb(V).
It was found that the +5 oxidation state is more stable. Therefore, Sb in the most cases has the coordination number 3.
Thanks
Respected all Professors,
probably i may be wrong ..but it seems me that coordination number of any element should depend on the surrounding atoms .....
it should depend on surrounding elemental atoms and lattice structure where the atom under consideration is situated...
so i think the above question could be well discussed if it could be known that in which composition Sb atoms are alloyed with....
Please make my doubt clear...
Sincerely Yours,
Suresh Sharma
As per definition of coordination number it is the nearest number of atoms surrounding any atom....
so it must be known in which lattice structure it is alloyed....
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