Laser-driven shock compression and equation of state of Fe$_2$O$_3$ up to 700 GPa

TL;DR

This paper presents the first laser-driven shock compression measurements of Fe₂O₃'s equation of state, extending data up to 700 GPa and revealing a significant volume drop and potential phase transitions.

Contribution

It provides new high-pressure data for Fe₂O₃ using laser-driven shocks, extending the Hugoniot curve to unprecedented pressures and identifying key volume and phase changes.

Findings

Observed a 10% volume drop at 86 GPa linked to spin transition

Extended Hugoniot data up to 700 GPa

No significant modifications observed above 250 GPa within error bars

Abstract

We report here the first equation of state measurements of Fe$_2$O$_3$ obtained with laser-driven shock compression. The data are in excellent agreement with previous dynamic and static compression measurements at low pressure, and extend the known Hugoniot up to 700 GPa. We observe a large volume drop of $\sim$10% at 86 GPa, which could be associated, according to static compression observations, with the iron spin transition. Our measurements also suggest a change of the Hugoniot curve between 150 and 250 GPa. Above 250 GPa and within our error bars, we do not observe significant modifications up to the maximum pressure of 700 GPa reached in our experiment.