Raman spectra of MCl-Ga 2 S 3 -GeS 2 (M = Na, K, Rb) glasses
Résumé
Abstract Raman spectra of (MY) x (Ga 2 S 3 ) 0.2−0.2 x (GeS 2 ) 0.8−0.8 x pseudo-ternary glassy systems (M = Na, K, Rb; Y = Cl, Br, I) were investigated systematically as a function of MY nature and alkali content. Raman spectroscopy of the Ga 3 S 3 -GeS 2 glassy matrix shows a complicated local structure: corner-sharing CS- and edge-sharing ES-GeS 4/2 tetrahedra, Ga-S triclusters and ETH-Ga 2 S 6/2 ethane-like units. The Ga 2 S 6/2 population decreases with increasing x related to a substitution of some bridging sulfur atoms around central Ga by terminal Y species with a respective decrease of the network rigidity. The formation of mixed Ga-(S,Y) environment is affected by the M + ion size and the MY concentration.
Domaines
Physique [physics]Origine | Fichiers éditeurs autorisés sur une archive ouverte |
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