Revealing the effect of medium-range structure on silicate glass hardness

Atomic structure determines physical properties, but for glassy materials, the nature of structure-property relationships remains ambiguous. Since glass properties are governed by both chemistry and structure, it is difficult to dissociate these two effects. Here, the sole effect of the structure on property is isolated by treating an industrial aluminosilicate glass with either thermal-annealing or pressure-quenching processes to produce glasses with varying densities and hardnesses (at constant composition). To explore the underlying structural origin of property changes, neutron total-scattering patterns of these glasses were measured. These results confirm the applicability of rigid-unit mode theory since the short-range tetrahedra were found to remain unaffected. In contrast, close correlations are derived between properties and medium-range structure (as encoded in various features of the first sharp diffraction peak). Overall, it reveals that the increase in the medium-range order is the structural origin of the extra extent of hardness increase beyond the densification effects.

Automated summary

Atomic structure plays a crucial role in determining the physical properties of materials, including glasses. In this study, the researchers investigated the structure-property relationships in glasses by manipulating their density and hardness through thermal-annealing and pressure-quenching processes. Neutron total-scattering patterns were used to analyze the structural changes, and the results indicated that medium-range structure changes were closely correlated with the properties, specifically hardness.