题目：New Iron carbides and oxides at earth’s out core conditions

报告人：李想 博士 法国欧洲同步辐射光源

报告时间：2026年7月27日（周一）上午10:00

报告地点：超硬实验综合楼5楼A514会议室

报告摘要：Understanding the formation, evolution, and dynamics of Earth’s core and those of other terrestrial planets requires precise knowledge of the relevant phase relations and physical properties of core materials. It is well established that the Earth’s core consists of an Fe–Ni alloy containing 3–7 wt% light elements, which account for its density deficit and reduced seismic velocities relative to pure Fe–Ni. However, the exact identity of these light elements remains debated, with S, C, O, H, and Si considered the most plausible candidates.

Among them, carbon is a strong candidate due to its high cosmic abundance and efficient incorporation into metallic iron during core formation. Moreover, Fe–C compounds can reproduce the low shear-wave velocities and high Poisson’s ratio observed in the Earth’s inner core. Oxygen has also been proposed as a key light element, as it may explain both the seismic-wave velocities and the density discontinuity at the inner-core boundary. Nevertheless, the phase relations and stability fields of Fe–O and Fe–C systems under core conditions remain poorly constrained.

In this study, we investigated the stable phases of the Fe–O and Fe–C systems using in situ single-crystal X-ray diffraction (XRD) and synchrotron Mössbauer spectroscopy (SMS) in diamond-anvil cells up to 230 GPa and 3000 K. We identified several new FeO and FeC phases and characterized their electronic and magnetic properties. These findings provide new insights into the seismic characteristics of Earth’s core and their implications for the geodynamo.

个人简介：李想，欧洲同步辐射博士后。主要研究领域为运用高温高压实验，模拟深部物质在极端条件下的物理化学性质，为地球及行星内部的物质组成及状态、动力学过程等基础科学问题提供约束依据，主要研究成果发表于Nat. Commun., Commun. Phys., PEPI. 等杂志。

主办单位：吉林大学高压与超硬材料全国重点实验室

吉林大学综合极端条件高压科学中心

吉林大学物理学院

吉林省物理学会

中国物理学会高压物理专业委员会