The thermal stability of a low Tg phosphate glass (Tg=339 °C), formulated in the ZnO–Na2O–P2O5 system, is
investigated in this contribution by Differential Scanning Calorimetry (DSC), X-Ray diffraction (XRD) and solid
state Nuclear Magnetic Resonance (NMR). DSC measurement indicates a very important Tx−Tg value (197 °C)
for the investigated composition compared to other lowTg phosphate glasses found in literature. XRD and 1D31P
solid stateNMRwere used tomonitor the isothermal crystallization process occurring at 60 °C above Tg (400 °C).
The mixture of phases formed after crystallization cannot be identified by XRD but 2D MAS-NMR experiment
provides valuable information about the composition and the structure of the unknown sample.