FeO的量子临界阶段跨越了地球下层地幔的条件
Wai-Ga D Ho1, Peng Zhang2, Kristjan Haule3
1Department of Physics and National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA.
Nature communications
|April 24, 2024
概括
在地球核心-地幔边界的氧化铁 (FeO) 呈现出不寻常的绝缘体-金属过渡,而不是利的金属化. 这种强烈相关的状态解释了我们星球深处观察到的地震和导电异常.
科学领域:
- 地质物理学 地质物理学
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
背景情况:
- 地球核心-地幔边界的区域可能富含FeO.
- 预计在极端的压力-温度 (P-T) 条件下,FeO会变成金属.
- 在这些条件下FeO的电子行为还不太清楚.
研究的目的:
- 在极端的P-T条件下研究B1-FeO的电子结构.
- 澄清FeO.O.对金属行为的转变.
- 解释核心-地幔边界的地球物理观测.
主要方法:
- 大规模的理论建模.
- 最先进的嵌入式动态平均场理论 (eDMFT).
- 阶段图分析. 阶段图分析.
主要成果:
- 在高温下压缩FeO导致轨道选择性绝缘体-金属过渡,而不是利的金属化.
- 在下层地幔的P-T条件下,FeO存在于一个量子临界状态.
- 这种状态的特点是t2g轨道中的电子扩散和eg轨道中的带间隙,产生适度的电导率 (~10^5 S/m).
结论:
- 丰富的FeO可以解释地球下层地幔异质中的低地震速度和高电导率.
- 观察到的现象与FeO在强烈相关的电子状态中一致.
- 这为核心-地幔边界的地球物理异常提供了统一的解释.
更多相关视频
11:50Metal-silicate Partitioning at High Pressure and Temperature: Experimental Methods and a Protocol to Suppress Highly Siderophile Element Inclusions
Published on: June 13, 2015
12.5K
12:20Sputter Growth and Characterization of Metamagnetic B2-ordered FeRh Epilayers
Published on: October 5, 2013
14.6K
相关概念视频
Ferromagnetism
2.4K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
2.4K
Phase Diagrams
40.6K
A phase diagram combines plots of pressure versus temperature for the liquid-gas, solid-liquid, and solid-gas phase-transition equilibria of a substance. These diagrams indicate the physical states that exist under specific conditions of pressure and temperature and also provide the pressure dependence of the phase-transition temperatures (melting points, sublimation points, boiling points). Regions or areas labeled solid, liquid, and gas represent single phases, while lines or curves represent...
40.6K
Phase Diagram
5.8K
The phase of a given substance depends on the pressure and temperature. Thus, plots of pressure versus temperature showing the phase in each region provide considerable insights into the thermal properties of substances. Such plots are known as phase diagrams. For instance, in the phase diagram for water (Figure 1), the solid curve boundaries between the phases indicate phase transitions (i.e., temperatures and pressures at which the phases coexist).
5.8K
Phase Transitions: Sublimation and Deposition
17.1K
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
17.1K
Phase Transitions: Melting and Freezing
12.4K
Heating a crystalline solid increases the average energy of its atoms, molecules, or ions, and the solid gets hotter. At some point, the added energy becomes large enough to partially overcome the forces holding the molecules or ions of the solid in their fixed positions, and the solid begins the process of transitioning to the liquid state or melting. At this point, the temperature of the solid stops rising, despite the continual input of heat, and it remains constant until all of the solid is...
12.4K
Phase Transitions
19.1K
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to...
19.1K
