J. Phys. IV France 7 (1997) C2-999-C2-1000
Short and Medium Range Order in Se1-xTex GlassesM. Majid1, J. Purans1, 2, S. Bénazeth1, 3 and C. Souleau1
1 Laboratoire de Chimie Minérale, Inorganique et Bioinorganique Châtenay-Malabry, Université Paris-Sud ; 91405 Paris, France
2 Institute of Solid State Physics, University of Latvia, 8 Kengaraga str., 1063 Riga, Latvia
3 LURE, Bât. 209D, 91405 Orsay, France
Complementary XAFS measurements (LURE and NSLS) of Se1-xTex glasses have been carried out on both the Se and Te K-edges at low and room temperatures. Using a multi-shell best fit analysis procedure, we have reconstructed the Se and Te local environment : (i) first shell intrachain nearest neighbors (Se-Se1, Se-Tel, Te-Se1, and Te-Te1) ; (ii) second shell intrachain (Se-Se2 and Se-Te2) and interchain next nearest neighbors (Se ←→ Se3 single scattering in the chains Se-Se1-Se3 and Se-Tel-Se3). For the first and second coordination shells we suggest that the intrachain chemical order increases with Te content. On the other hand, we propose a model of random distribution of Se and Te atoms between the chains.
© EDP Sciences 1997