Zinc alkali phosphate based glasses have been extensively studied
[1–8] because of their low glass transition temperature and good
stability, making them potential candidates for technical applications
(low temperature sealing glasses, special radioactive wastes host
matrixes, laser amplification glasses, low temperature anti-oxidation
coatings…) and for the development of glass/polymer composites. The
chemical durability (resistance to water) of such system has been
previously investigated [4,5,8,9] but only sparse information is available
on the thermal stability (resistance to thermal treatments) of such
glasses [10], although this property rules many of the applications
previously mentioned. Indeed,many applications require the glass to be
submitted to thermal treatments above Tg and are severely limited
when devitrification occurs. Therefore, the crystallization process needs
to be investigated, characterized and understood in order to be
controlled and to produce glasses with improved thermal stability.
We investigated the thermal stability under isothermal treatment of
a zinc alkali phosphate glass with the 46.6ZnO–20.0Na2O–33.4P2O5
molar composition. This formulation comes froma simplification of the
compositions reported in Ref. [3–5]. The glass investigated here is
designed to have a dimeric structure (O/P=3.5) and the ratio between
ZnO and Na2Owas setup to a value of 2.33, representative of several low