Structural evolution of iron oxides melts at Earth's outer-core pressures.
СтатьяНазвание и аннотация: Перевод в очереди
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Crépisson Céline, Fitzgerald Mila, Peake Domenic, Heighway Patrick G, Stevens Thomas, Descamps Adrien, McGonegle David, Amouretti Alexis, Alaa El-Din Karim K, Andrzejewski Michal, Azadi Sam, Brambrink Erik, Camarda Carolina, Chin David A, Di Dio Cafiso Samuele, Coutinho Dutra Ana, Höppner Hauke, Yamamoto Kohdai, Karamched Phani S, Konôpková Zuzana, Nakatsutsumi Motoaki, Ozaki Norimasa, Polsin Danae N, Schwinkendorf Jan-Patrick, Shoulga Georgiy, Strohm Cornelius, Tang Minxue, Taylor Harry, Toncian Monika, Wang Yizhen, Yao Jin, Gregori Gianluca, Wark Justin S, Appel Karen, Harmand Marion, Vinko Sam M
Аннотация
Oxygen and other light elements comprise up to 5 wt% of the Earth's outer-core, and may significantly influence its physical properties and the operation of the geodynamo. Here we report in situ X-ray diffraction measurements of Fe, Fe + 4.5 FeO (atomic proportion), and Fe2O3 melts at 177-440 GPa, achieved using laser-driven shock compression at an x-ray free-electron laser. The melts exhibit Fe-O coordination numbers between 4.0(0.4) and 4.5(0.4), indicating predominantly four-fold coordination environments. These coordination states are significantly smaller than those of Fe-bearing lower-mantle phases such as bridgmanite and ferropericlase. Shorter Fe-Fe interatomic distances in compressed iron oxide melts drive the denser packing relative to ambient melts, while the structural differences between Fe + 4.5 FeO and Fe2O3 melts under shock indicate that the oxidation state modulates oxygen solubility in liquid Fe. At 177 GPa ( ~ 380 km below the core-mantle boundary) and 3800 K, Fe2O3 melts exhibit higher Fe-O coordination, suggesting that local variations in oxygen content could contribute to the stratification in the uppermost outer-core inferred from seismological and geomagnetic observations.