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Characterization of Thermal Transport in One-dimensional Solid Materials
Published on: January 26, 2014
地球下层地幔中的辐射导电性
Alexander F Goncharov1, Benjamin D Haugen, Viktor V Struzhkin
1Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road NW, Washington, DC 20015, USA. goncharov@gl.ciw.edu
Nature
|November 14, 2008
概括
下层地幔酸矿中的铁铁 (Fe3+) 显著影响热导率. 这一发现表明辐射导电率低于以前的估计,影响了地幔演变和羽毛动力学.
科学领域:
- 地质物理学 地质物理学
- 矿物物理 矿物物理
- 高压科学科学 高压科学
背景情况:
- 铁的氧化状态影响地球的生态化学循环和地幔特性.
- 低地幔矿物质中的铁,如酸矿石和铁烯酸,会影响热导率和核心热量流.
- 铁氧化状态对地球深层的运输特性的影响仍然不太清楚.
研究的目的:
- 调查铁氧化状态对下层地幔矿物质辐射导热性的作用.
- 确定酸铁 (Fe3+) 度如何影响酸矿中的光学吸收和辐射导电性.
- 为地球下层地幔的热状态和演变提供新的见解.
主要方法:
- 在高压下 (高达133 GPa) 和高温下 (高达800 K) 测量了酸矿和铁烯酸的光学吸收光谱.
- 分析了光谱数据,以确定不同铁物种 (Fe2+,Fe3+) 和电荷转移机制的贡献.
- 基于实验光学吸收数据计算的压力依赖的辐射热导率 (k(rad)).
主要成果:
- 在酸盐矿中,光学吸收主要是由O-Fe(3+) 电荷转移和Fe(3+) -Fe(2+) 间隔过渡驱动的.
- 铁3+) 度直接控制了酸矿中导热的辐射成分.
- 辐射导电性 (k(rad)) 估计比先前推断的低2-5倍,铁烯酶的温度依赖程度最低,高达60 GPa.
结论:
- 铁酸铁 (Fe3+) 的度是控制地球下层地幔酸矿中辐射导热的关键因素.
- 低于预期的辐射导电性对地幔动力学有重大影响,包括热化学羽毛的产生和稳定性.
- 这项研究完善了我们对地球深层的热传递及其对行星进化影响的理解.
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