Glass formation in the Sb2O3-SbPO4-WO3 system

Glasses in the ternary system (Sb 2 O 3 ) (0.6-x) (SbPO 4 ) (0.4) (WO 3 ) (x) , with composition 0.1 £ x £ 0.5 were studied. The structural changes due to the replacement of Sb 2 O 3 by WO 3 have been investigated. It was found that the incorporation of WO 3 enhances the thermal stability of the glasses against devitrification when compared to the binary Sb 2 O 3(0.6) - SbPO 4(0.4) composition. The connectivity of the network increases with WO 3 content which is consistent with the high values of the glass transition temperature. Raman studies suggest that WO 3 incorporation breaks the primary network, constituted by antimony oxide, while a second network containing WO 6 octahedral units is built up. Thermal and structural properties were evaluated by differential scanning calorimetry, infrared and Raman spectroscopies, 31 P Magic Angle Spinning NMR and X-ray absorption near edge structure (XANES) at L 1 and L 3 edges of Sb and L 1 edge of W atoms.