Melting and Pressure-Induced Amorphization of Quartz

TL;DR

This paper uses molecular dynamics simulations to suggest that pressure-induced amorphization of quartz is related to melting, showing structural similarities between pressure glasses and rapidly quenched thermal glasses.

Contribution

It provides a molecular dynamics perspective linking quartz amorphization to melting, a novel insight into pressure-induced phase changes in silica.

Findings

Pressure-induced amorphization line coincides with the melting line in quartz.

Pressure glasses resemble rapidly quenched thermal glasses structurally.

Melting may be the physical mechanism behind pressure-induced amorphization.

Abstract

It has recently been shown that amorphization and melting of ice were intimately linked. In this letter, we infer from molecular dynamics simulations on the SiO2 system that the extension of the quartz melting line in the metastable pressure-temperature domain is the pressure-induced amorphization line. It seems therefore likely that melting is the physical phenomenon responsible for pressure induced amorphization. Moreover, we show that the structure of a "pressure glass" is similar to that of a very rapidly (1e+13 to 1e+14 kelvins per second) quenched thermal glass.