LULI2000 - Exploring Iron oxide phase diagrams and equation of states under extreme pressure and temperature conditions (M. Harmand)
Iron-oxygen (Fe-Q) binary systems are of the utmost importance for planetary evolution. However, their phase diagrams and physical properties at extreme pressure and temperatures are poorly known. As an example, the recent discoveries of exotic stoichiometries demonstrates that our understanding of these binary systems is limited and that high pressure mineralogy is far more complex than we previously thought. We propose to study a selection of iron oxides under laser shock compression, up to 800 GPa and beyond, in order to extend the knowledge oftheir phase diagram far above the existing static compression experiments. We will measure Equation Of States (EOS) and reflectivity of Fe-O compounds (Fe203, Fe304, FeO and in between mixtures by order of priority), and will explore their phase diagrams by detecting Hugoniot anomalies and abrupt reflectivity changes. While su ch measurements are fundamental for geoscience, they are often limited to restricted range of pressure and temperature wh en using static compression or by its limited precision when using laser compression. Indeed, error bars associated with EOS measurements have been 50 far a critical missing piece of the puzzle and are still limiting extrapolation of the shock compression experiments to geoscience applications. Here we propose to use a unique target design from the IMPMC laboratoryto produce high-precision shock velocity measurements.
LULI2000 - S45-S46/2019