论文标题
在地球深内部条件下，铁中铁的相变和旋转状态
Phase transitions and spin-state of iron in FeO at the conditions of Earth's deep interior
论文作者
论文摘要
含铁氧化物会经历一系列压力诱导的电子，自旋和结构过渡，这些氧化物可能在地球地幔和外核中引起地震异常和动态不稳定性。 We employ x-ray diffraction and x-ray emission spectroscopy along with state-of-the-art density functional plus dynamical mean-field theory (DFT+DMFT) to characterize the electronic structure and spin states, and crystal-structural properties of wüstite (Fe$_{1-x}$O) -- a basic oxide component of Earth's interior -- at high pressure-temperature conditions up to 140 GPa and 2100 K. We find该FEO在压力下表现出复杂的多态性，其压缩行为与电子旋转和晶体相跃迁相关，并导致散装模量发生实质性变化。我们的结果揭示了存在一个高压相，其特征在于地球核心掩膜边界的压力温度条件下以金属高旋转状态为特征。地幔底部附近的高旋转金属铁的存在可以显着影响地球深内部的地球物理和地球化学特性。
Iron-bearing oxides undergo a series of pressure-induced electronic, spin and structural transitions that can cause seismic anomalies and dynamic instabilities in Earth's mantle and outer core. We employ x-ray diffraction and x-ray emission spectroscopy along with state-of-the-art density functional plus dynamical mean-field theory (DFT+DMFT) to characterize the electronic structure and spin states, and crystal-structural properties of wüstite (Fe$_{1-x}$O) -- a basic oxide component of Earth's interior -- at high pressure-temperature conditions up to 140 GPa and 2100 K. We find that FeO exhibits complex polymorphism under pressure, with abnormal compression behavior associated with electron-spin and crystallographic phase transitions, and resulting in a substantial change of bulk modulus. Our results reveal the existence of a high-pressure phase characterized by a metallic high-spin state of iron at about the pressure-temperature conditions of Earth's core-mantle boundary. The presence of high-spin metallic iron near the base of the mantle can significantly influence the geophysical and geochemical properties of Earth's deep interior.
