| Abstract Scope |
Far-from-equilibrium conditions drive transformations to metastable phases with unique, emergent properties otherwise inaccessible. This study presents recent experimental insight into phase transformations in oxide materials subjected to extreme conditions, such as relativistic ion irradiation and high-energy mechanical action. Using advanced characterization techniques, including synchrotron X-ray diffraction and neutron total scattering, we examined multi-scale structural changes in binary dioxides (AO2) and sesquioxides (A2O3), as well as complex oxides (e.g., A2B2O7 pyrochlore), under systematically varied experimental parameters, such as ion species, ion energy, milling tools, and operating speeds. These investigations reveal a variety of structural transformations, including transitions to high-temperature and high-pressure polymorphs unrecoverable by conventional approaches. Certain materials even exhibit phases outside their conventional P-T diagram, characterized by unconventional order across multiple length scales and complex domain wall structures. These findings highlight how nonequilibrium processes create metastable phases with unique properties, offering insights and pathways for discovering novel materials and properties. |