Structural characterizations of As-Se-Te glasses
Résumé
The atomic structure of chalcogenide glasses As3Se7−xTex (0 ≤ x ≤ 3) and As2Se3−xTex (0 ≤ x ≤ 2.5) has been investigated by different methods. Short-range order has been studied by Wide-Angle X-ray Scattering (WAXS). 77Se NMR as well as Raman and infrared measurements were also performed on the different compositions. We show that the progressive introduction of tellurium in As3Se7−xTex or As2Se3−xTex induces breaking of Se-Se bonds and the formation of AsSe3−xTex pyramidal units. Experimental data also reveal the absence of Te-Te bonds even in the tellurium richest composition which let suppose a homogeneous repartition of tellurium atoms in the glassy network.