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美国Texas大学的Jung-Fu “Afu” Lin 教授访问我组进行学术交流
美国Texas大学的Jung-Fu “Afu” Lin 教授于2010年9月27日访问我组并做了题为“Solid State Geophysics under Extreme Environments: from Electronic States to Earth’s Interior”的学术报告。
a diamond anvil cell. His major research efforts aim at understanding the nature of the Earth's interior and other planetary bodies through direct examinations of the physics and chemistry of planetary materials at relevant conditions. Another research interest focuses on the behavior of volatiles such as H2O and CO2 under extreme conditions, as they are essential to our understanding of myriad problems&nb sp;in physics, chemistry, biology, and planetary sciences. His research results have been published on Science, Nature, Nature Materials, Nature Geoscience, PRL, PRB, and other international journals。
Extreme pressure-temperature environments can cause fundamental changes in the atomistic and electronic structures of condensed matters that are of great interest to a wide range of physics, chemistry, and geophysics problems. In Particular, Earth's interior is subject to crushing pressures of up to 360 GPa and scorching temperatures of up to 6000 K that can only be directly accessed by limited seismic and geochemical probes. These in turn provide excellent natural testing grounds for understanding materials properties under extreme conditions. Laboratory studies on properties of candidate planetary materials under extreme environments is thus crucial to understanding a plethora of outstanding phenomena in the deep Earth ranging from volcanic eruptions to mantle convections, from geomagnetic fields to core geodynamo, from global water and carbon cycles to origins of the Earth's oceans and diamonds, to name a few. Recent advances in high-pressure laser and synchrotron X-ray spectroscopic techniques now permit direct examinations of the microscopic properties of earth materials at pressure-temperature conditions of the deep Earth.&n bsp;Similar to solid-state physics methods, these mineral physics studies consider how the large-scale processes of earth materials result from their atomic-scale properties occurring deep inside the Earth. In this talk, I will use my recent research results from diamond anvil cell experiments as examples to highlight these solid state geophysics efforts. Specifically, I will show how recently observed electronic spin transitions of iron, the most abundant transition metal in the Earth, affect seismic and transport properties of the lower mantle, how phonon dispersions ;of iron alloys have been applied to decipher the composition and formation of the remotest Earth's core, and how physicists and geophysicists are working closely to interrogate novel materials properties such as iron-based superconductors that may help address the world's energy future. Future challenges and research opportunities in materials properties under extreme environments will also be presented so as to stimulate CAS scientists to explore this new frontier collaboratively.