Collaborative Research: Effects of ferric iron on heat transport in Earth's mantle

地幔中的热传输影响板块构造、火山活动和磁场。材料如何携带热量随深度、温度和成分而变化。这个项目测试氧化铁如何改变地幔中的热传输。构造板块中的氧化富铁岩石俯冲到地幔中，并可能在地幔底部富集。在这个项目中，研究人员将进行实验，以生长与地幔相关的晶体，其成分包括氧化铁。他们将在高压和高温下测量这些晶体中的热流。这些结果将使他们能够研究地球大气层和地幔岩石之间的反应如何影响地球的动力学，因为它们具有传输热量的能力。该项目将在密歇根州立大学启用一项新技术，并通过实验和共享研究生和博士后学者培训，在密歇根州和台湾的研究人员之间建立合作。本课程将介绍台湾地质及地球物质的热性质.地幔硅酸盐的热导率调节地球的动力学。最近的研究调查了铁和压力诱导的自旋转变对地幔矿物热导率的影响。然而，这些研究仅限于还原成分，如铁方镁石和富亚铁的硼镁石。研究人员将在金刚石对顶砧单元中使用超快时域热反射（TDTR）光谱来确定氧化富铁桥镁石和后钙钛矿的晶格热导率。他们将隔离的压力驱动的自旋配对转变的影响，在铁-铁轴承bridgmanite和铝与铁对热传输的影响。密歇根州立大学、密歇根大学和台湾中央研究院之间的这项合作将联合收割机在晶体生长、极高压和温度实验方面的互补专业知识结合起来，该奖项反映了NSF的法定使命，并通过使用基金会的智力价值进行评估，被认为值得支持和更广泛的影响审查标准。

Heat transport in Earth’s mantle affects plate tectonics, volcanism, and the magnetic field. How materials carry heat varies with depth, temperature, and composition. This project tests how oxidized iron changes heat transport in the mantle. Oxidized iron-rich rock in tectonic plates subducts to the mantle and may be enriched at the base of the mantle. In this project, researchers will conduct experiments to grow mantle-relevant crystals with compositions including oxidized iron. They will measure heat flow in these crystals at high pressures and temperatures. The results will allow them to examine how reactions between Earth's atmosphere and mantle rock affect the Earth’s dynamics as a consequence of their ability to transport heat. This project will enable a new technique at Michigan State and establish collaboration between researchers in Michigan and Taiwan through experiments and shared graduate student and postdoctoral scholar training. Michigan undergraduate students will be introduced to geology of Taiwan and thermal properties of Earth materials. Thermal conductivity of mantle silicates modulates the Earth’s dynamics. Recent studies have investigated the effects of iron and pressure-induced spin transitions on thermal conductivity in mantle minerals. However, these studies have been limited to reduced compositions such as ferropericlase and ferrous-iron-rich bridgmanite. The researchers will use ultrafast time-domain thermo-reflectance (TDTR) spectroscopy in diamond anvil cells to determine the lattice thermal conductivity of oxidized ferric-iron-rich bridgmanite and post-perovskite. They will isolate the effects of the pressure-driven spin pairing transition in ferric-iron-bearing bridgmanite and effects of aluminum versus ferric iron on heat transport. This collaboration between Michigan State University, the University of Michigan, and the Academia Sinica in Taiwan will combine complementary expertise in crystal growth, extreme high pressure and temperature experiments, and heat flow measurement to measure how differences in oxidation in the mantle impact mantle convection.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.