Direct Observation of Shock‐Induced Disordering of Enstatite Below the Melting Temperature

DOI HANDLE Web Site Web Site Web Site View 1 Remaining Hide 42 References Open Access

Search this article

Description

<jats:title>Abstract</jats:title><jats:p>We report in situ structural measurements of shock‐compressed single crystal orthoenstatite up to 337 ± 55 GPa on the Hugoniot, obtained by coupling ultrafast X‐ray diffraction to laser‐driven shock compression. Shock compression induces a disordering of the crystalline structure evidenced by the appearance of a diffuse X‐ray diffraction signal at nanosecond timescales at 80 ± 13 GPa on the Hugoniot, well below the equilibrium melting pressure (>170 GPa). The formation of bridgmanite and post‐perovskite have been indirectly reported in microsecond‐scale plate‐impact experiments. Therefore, we interpret the high‐pressure disordered state we observed at nanosecond scale as an intermediate structure from which bridgmanite and post‐perovskite crystallize at longer timescales. This evidence of a disordered structure of MgSiO<jats:sub>3</jats:sub> on the Hugoniot indicates that the degree of polymerization of silicates is a key parameter to constrain the actual thermodynamics of shocks in natural environments.</jats:p>

Journal

References(42)*help

See more

Related Projects

See more

Report a problem

Back to top