Structural study of glasses in the system B2O3-Bi2O3-La2O3-WO3

New multicomponent (100 (x- y)).(0.6B(2)O(3).0.4Bi(2)O(3))center dot xLa(2)O(3.)yWO(3), x = 0, 10; y = 0 40 mol% glasses were obtained by melt quenching technique and its structure were examined by infrared and Raman spectroscopies. Based on the obtained spectral data it was suggested that in the absence of La2O3, tungsten incorporates into boro-bismuthate network in small quantities through Bi3+ and B-O-W bonds are not formed. Accumulation of Bi-O-W bonds stimulates crystallization processes. La2O3 is crucial to connect tungstate units with boro-bismuthate glass matrix and to realize amorphous network with their participation. It was supposed that in glasses with higher WO3 content (30 and 40 mol%) two inconsisted glass networks are formed bismuth borate one built up by BO3, BO4, BiO6 units and tungstate one, built up mainly by WO6. These networks are interconnected through lanthanum.