Abstract
Samples with chemical composition (1-x) [0.95NaPO3-0.05Na2B4O7]-x Nb2O5 have been annealed at T≥750°C. For x≥0.3, the presence of Na4Nb8P4O32 crystalline phase were detected by X ray diffraction. The size and the distribution of micro-crystallites in the bulk glass samples were determined in relation to the thermal treatment. The crystallized glasses were studied by Raman micro probe and 31P MAS NMR and discussed in comparison with the glassy samples.
