Despite their transformative role in our society, oxide glasses remain brittle. Although extrinsic postprocessing techniques can partially mitigate this drawback, they come with undesirable side effects. Alternatively, topological engineering offers an attractive option to enhance the intrinsic strength and damage resistance of glass. On the basis of this approach, we report here the discovery of a novel melt-quenched lithium aluminoborate glass featuring the highest crack resistance ever reported for a bulk oxide glass. Relying on combined mechanical and structural characterizations, we demonstrate that this unusual damage resistance originates from a significant self-adaptivity of the local atomic topology under stress, which, based on a selection of various oxide glasses, is shown to control crack resistance. This renders the lithium aluminoborate glass a promising candidate for engineering applications, such as ultrathin, yet ultrastrong, protective screens.

Sodium aluminoborate glasses are found to exhibit favorable mechanical properties, especially high crack resistance, due to their relatively low resistance to network compaction during sharp-contact loading. We here reveal the origin of the high crack resistance by investigating changes in structure and mechanical properties in compositions ranging from peralkaline to peraluminous and by varying the pressure history through an isostatic N 2-mediated pressure treatment at elevated temperature. This approach allows us to study the composition dependence of the ease of the glassy network compaction and the accompanying changes in structure and properties, which shed light on the processes occurring during indentation. Through solid state NMR measurements, we show that the network densification involves an increase in the average coordination number of both boron and aluminum and a shortening of the sodium-oxygen bond length. These changes in the short-range order of the glassy networks manifest themselves as an increase in, e.g., density and indentation hardness. We also demonstrate that the glasses most prone to network compaction exhibit the highest damage resistance, but surprisingly the crack resistance scales better with the relative density increase achieved by the hot compression treatment rather than with the extent of densification induced by indentation. This suggests that tuning the network structure may lead to the development of more damage resistant glasses, thus addressing the main drawback of this class of materials.

The dynamics of glass is of importance in materials science but its nature has not yet been fully understood. Here we report that a verification of the temperature dependencies of the primary relaxation time or viscosity in the ultraslowing/ultraviscous domain of glass-forming systems can be carried out via the analysis of the inverse of the Dyre–Olsen temperature index. The subsequent analysis of experimental data indicates the possibility of the self-consistent description of glass-forming low-molecular-weight liquids, polymers, liquid crystals, orientationally disordered crystals and Ising spin-glass-like systems, as well as the prevalence of equations associated with the ‘finite temperature divergence’. All these lead to a new formula for the configurational entropy in glass-forming systems. Furthermore, a link to the dominated local symmetry for a given glass former is identified here. Results obtained show a new relationship between the glass transition and critical phenomena.