Stishovite formation at very low pressures in soda-lime glass

We show for the first time that amorphous soda-lime glass undergoes polymorphic transformation to its densest crystalline stishovite phase at only ~5 GPa of pressure and room temperature, by uniaxially compressing the soda-lime glass nanopillars of 500 nm diameter and observing the post-deformed pillars under transmission electron microscopy. This contrasts with the recent shock-compression experiments of amorphous fused silica glass plates which report a pressure threshold of 34 GPa for stishovite formation. Our findings support recent dislocation dynamics simulations on W pillars which show that small domain size acts as a proxy for high temperature, thereby reducing the pressure threshold.