| Abstract Scope |
The design of compositionally complex functional glasses increasingly requires predictive frameworks that extend beyond empirical composition–property correlations toward mechanistic understanding. This presentation discusses the chemo-structural descriptors governing nepheline crystallization in sodium aluminoborosilicate glasses, with particular emphasis on the roles of Fe2O3 and P2O5. By combining multinuclear MAS NMR, Raman, and Mössbauer spectroscopy, along with melt rheology and crystallization studies, the structural rearrangements induced by iron and phosphorus are correlated with changes in melt properties and crystallization behavior. The results demonstrate that iron preferentially forms Fe–O–B and Fe–O–Si linkages, whereas phosphorus promotes Fe–O–P and Al–O–P environments that suppress the Si–O–Al linkages required for nepheline formation. These findings establish chemo-structural descriptors that provide a rational basis for designing crystallization-resistant high-level nuclear waste glasses and other multicomponent functional glass systems. |