J. Phys. Colloques
Volume 42, Numéro C4, Octobre 1981Proceedings of the Ninth International Conference on Amorphous and Liquid Semiconductors
|Page(s)||C4-951 - C4-954|
J. Phys. Colloques 42 (1981) C4-951-C4-954
RADIAL DISTRIBUTION FUNCTION STUDIES OF GLASSY GERMANIUM-SILVER-CHALCOGEN ALLOYSL.C. Bourne1, S.C. Rowland1 and A. Bienenstock2
1 Department of Physics, Andrews University, Berrien Springs Michigan 49104, U.S.A.
2 Department of Materials Science, Stanford University, Stanford, California 94305, U.S.A.
X-ray diffraction radial distribution function (rdf) studies have been performed on 15 different alloys in the glassy GexAgy X1-x-y systems, where X is S or Se. Assumption of fourfold Ge coordination and no S-S bonds in the sulfur alloys leads to direct determination of Ag coordination numbers in the range 3 to 4. The further assumption that the S and Se materials have the same near neighbor coordination numbers leads to the determination of chalcogen coordination numbers which increase with y to approximately 4. The resulting coordination numbers are, on the average, consistent with the 8-N rule. The Ag-X distances are closer to the covalent than to the ionic distances and are consistent with those in the crystalline compound Ag8GeX6.