40th International Workshop on High Energy Density Physics with Intense Ion and Laser Beams

Iron–oxygen (Fe-O) 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, recent static compression experiments have demonstrated the existence of new iron oxide stoichiometries at high pressure and temperature such as FeO2 [1][2], Fe4O5 [3], Fe5O6 [4]. These discoveries, with the wide variety of iron oxides phases existing at high pressure [5], highlight the complexity of iron-oxygen phase diagram in extreme condition. In this context, measurements of physical properties, phase transition processes and phase diagrams of Fe-O systems with laser shock compression techniques offer unique opportunities to extend the actual pressure and temperature ranges of such studies. Here, I will present main results from a laser shock experiment at the ID24 ESRF beamline using time-resoved X-ray absorption measurement on Fe2O3 samples. In addition, I will show a preliminary analysis of a very recent experiment performed at LULI 2000 to measure equation of state along the Fe2O3 Hugoniot and above 500GPa. I will also describe the experimental setups, as well as the target designs and fabrications used for both experiments. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (ERC PLANETDIVE grant agreement No 670787). References : [1] Q. Hu and al., “FeO2 and FeOOH under deep lower-mantle conditions and Earth’s oxygen–hydrogen cycles” Nature, 534, 241 – 244, (2016). [2] E. Boulard et al., “Ferrous iron under oxygen-rich conditions in the deep mantle” Geophysical Research Letter, 46, 1348 – 1356, (2019). [3] B. Lavina et al., “Discovery of the recoverable high-pressure iron oxide Fe4O5” Proceedings of the National Academy of Sciences of the United States of America, 108(42), 17281–5, (2011). [4] B. Lavina et al., “Unraveling the complexity of iron oxides at high pressure and temperature: Synthesis of Fe5O6” Science Advances, 1, e1400260, (2015). [5] E. Bykova et al., “Structural complexity of simple Fe2O3 at high pressures and temperatures” Nature communication, 7, 10661, (2016).