Spin crossover in FeO under shock compression

Spin crossover in FeO under shock compression
L’elia Libon, Alessandra Ravasio, Silvia Pandolfi, Yanyao Zhang, Xuehui Wei, Jean-Alexis Hernandez, Hong Yang, Amanda J. Chen, Tommaso Vinci, Alessandra Benuzzi-Mounaix, Clemens Prescher, Franc{c}ois Soubiran, Hae Ja Lee, Eric Galtier, Nick Czapla, Wendy L. Mao, Arianna E. Gleason, Sang Heon Shim, Roberto Alonso-Mori, Guillaume Morard
arXiv:2603.17136v1 Announce Type: cross
Abstract: FeO (w”ustite), which exhibits complex electronic and structural properties with increasing pressure and temperature, is a key mineralogical phase for understanding deep planetary interiors. However, direct measurements of its spin state at high-pressure and temperature remain challenging in static compression experiments. Here, we employ laser-driven shock compression to extend the FeO principal Hugoniot up to $sim$900 GPa and perform in situ X-ray diffraction and X-ray emission spectroscopy up to 250 GPa, probing FeO’s crystal structure and spin state. We demonstrate a continuous spin crossover of iron in FeO over a broad pressure range, with the high-spin state persisting beyond Earth’s core-mantle boundary (CMB) conditions. These observations provide new experimental constraints on iron spin state at extreme conditions essential for geophysical models of (exo)planetary interiors.arXiv:2603.17136v1 Announce Type: cross
Abstract: FeO (w”ustite), which exhibits complex electronic and structural properties with increasing pressure and temperature, is a key mineralogical phase for understanding deep planetary interiors. However, direct measurements of its spin state at high-pressure and temperature remain challenging in static compression experiments. Here, we employ laser-driven shock compression to extend the FeO principal Hugoniot up to $sim$900 GPa and perform in situ X-ray diffraction and X-ray emission spectroscopy up to 250 GPa, probing FeO’s crystal structure and spin state. We demonstrate a continuous spin crossover of iron in FeO over a broad pressure range, with the high-spin state persisting beyond Earth’s core-mantle boundary (CMB) conditions. These observations provide new experimental constraints on iron spin state at extreme conditions essential for geophysical models of (exo)planetary interiors.