Abrupt crystallization from shock-compressed CaSiO3 glass

TL;DR

This study reveals ultrafast crystallization of CaSiO3 glass into perovskite at ~100 GPa under shock, with nanosecond nucleation and grain growth influenced by diffusion and release waves.

Contribution

First in situ observation of shock-induced rapid crystallization of CaSiO3 glass into perovskite at extreme pressure.

Findings

Crystallization occurs within ~1.7 ns at 100 GPa.

Final grain size is approximately 20 nm.

Release waves influence nucleation and grain growth.

Abstract

We have performed in situ time-resolved X-ray diffraction at ~100 GPa on laser-shocked CaSiO3 glass to investigate the glass-to-crystal transition. At this extreme pressure, we observe the ultrafast crystallization of the CaSiO3 perovskite structure from the compressed amorphous phase, with a typical nucleation time of 1.69 +/- 0.10 ns and a final grainsize of ~20 nm. The grain size temporal evolution suggest a diffusion controlled transformation. Moreover, the observed concomitant explosive grain growth together with the release wave arrival into shocked CaSiO3 also suggests a role of the release in the nucleation process.