Soda-lime silicate glass under hydrostatic pressure and indentation: a micro-Raman study

Area of Science:

• Materials Science
• Solid State Chemistry
• Spectroscopy

Background:

• Understanding the mechanical and structural behavior of glass under extreme conditions is crucial for material design and application.
• Soda-lime silicate glass, commonly used in windows, exhibits complex responses to applied stress.
• Previous studies have explored glass behavior under pressure, but detailed local structural analysis remains challenging.

Purpose of the Study:

• To investigate the plastic behavior and structural evolution of window glass under high hydrostatic pressure and Vickers indentation.
• To characterize pressure-induced structural changes, specifically focusing on silicate speciation (Q(n) species).
• To establish an accurate calibration curve for Raman micro-spectroscopy analysis of glass structure and to map local density variations.

Main Methods:

• Raman micro-spectroscopy was employed to analyze the structural changes in window glass.
• High hydrostatic pressure and Vickers indentation were used to induce plastic deformation.
• Micro-Raman mapping with high spatial resolution was performed to characterize local density variations.

Main Results:

• Pressure-induced irreversible structural changes were observed, characterized by an increase in Q(2) silicate species at the expense of Q(3) species.
• A highly accurate calibration curve for Raman analysis of silicate speciation was established for the first time.
• Local density variations in indented window glass were successfully mapped, revealing detailed structural responses at a micro-scale.

Conclusions:

• The study demonstrates significant pressure-induced depolymerization in window glass, altering its silicate network structure.
• Raman micro-spectroscopy is a powerful tool for characterizing local structural changes and density variations in stressed glass.
• The findings highlight differences in the mechanical response of window glass compared to pure SiO(2) glass under high stress.