![]() ![]() (13,14) Clarifying the structural transitions in oxide glass during irreversible densification is, therefore, vital for rebuilding the geological processes in planetary surfaces and interiors. (11,12) Crystalline and noncrystalline aluminum-rich oxides in chondrites under shock compression and recovery record key information on high-pressure (HP) impact events in the early solar system. (10) Oxide glasses are among the major constituents of the basaltic oceanic crust that form deep in Earth’s mid-ocean ridges and are subject to densification during subduction, while they may form crystalline materials in contact with aqueous fluids. (4−9) The detailed nature of the permanent densification of oxide glass is crucial for understanding deformation mechanisms under sharp contact loading, as well as manufacturing glasses with tunable physical characteristics. ![]() (1−3) Deciphering the nature of pronounced irreversible densification is a long-standing interest in materials science since densified glasses tend to show improved hardness and fracture toughness. Oxide glasses undergo irreversible deformation upon extreme compression, permanently modifying the density and related properties after pressure release. These results extend the knowledge on densification of the previously unattainable pressure conditions and contribute to understanding the origin of mechanical strengthening of the glasses. Based on a statistical thermodynamic model, the stepwise changes in the Al fractions of oxide glasses and the effects of network polymerization on the densification paths are quantified. The results constrain the densification path through coordination transformation of Al cations. Here, we report the first high-resolution NMR spectra of oxide glass compressed by diamond anvil cells at room temperature, extending the pressure record of such studies from 24 to 65 GPa. High-resolution NMR spectroscopy quantifies atomic-level structural information on densified glasses however, its application is limited to the low-pressure range due to technical challenges. Deciphering the structural evolution in irreversibly densified oxide glasses is crucial for fabricating functional glasses with tunable properties and elucidating the nature of pressure-induced anomalous plastic deformation in glasses.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |