Shear softening of earth's inner core as indicated by its high poisson ratio and elastic anisotropy  

作　　者：Zhongqing Wu Wenzhong Wang 

机构地区：[1]Laboratory of Seismology and Physics of Earth's Interior,School of Earth and Space Science,University of Science and Technology of China,Hefei 230026,China [2]Mengcheng National Geophysical Observatory,University of Science and Technology of China,Hefei 230026,China [3]CAS Center for Excellence in Comparative Planetology,University of Science and Technology of China,Hefei 230026,China

出　　处：《Fundamental Research》2025年第1期264-268,共5页自然科学基础研究(英文版)

摘　　要：Earth's inner core exhibits an unusually high Poisson ratio and noticeable elastic anisotropy.The mechanisms responsible for these features are crucial to understanding the nature of Earth's core.Although different mechanisms have been proposed,few can explain both observations simultaneously.The results of this study indicated that the crystal with noticeable shear softening would have strong anisotropy and an exceptionally high Poisson ratio simultaneously.Body-centered-cubic(bcc)iron exhibits shear instability at inner-core pressures and can be dynamically stabilized by high temperature and the presence of light elements.The bcc-lattice iron alloy could have strong anisotropy and a Poisson ratio of Earth's inner core before shear instability.Identifying which light elements can stabilize the bcc-lattice iron alloy will provide an independent constraint on the chemical composition of the inner core.

关 键 词：ELASTICITY Crystal structure Iron alloy Earth’s interior Composition 

分 类 号：P315.3[天文地球—地震学]