短程有序稳定地球内核中的立方铁合金
Short-range order stabilizes a cubic Fe alloy in Earth's inner core
AI总结：
本研究通过深度学习辅助的混合蒙特卡罗模拟，测定内核边界压力下Fe-Si合金的相图和声速，发现硅原子短程有序稳定bcc相，且该固溶体能更好解释内核的关键地球物理特征。
摘要：
我们通过深度学习辅助的混合蒙特卡罗模拟，以从头算精度测定了对理解地球核心至关重要的Fe-Si二元合金在内核边界压力下的相图和声速。在接近熔化温度处出现了复杂的相图，其中观察到体心立方（bcc）相的重入现象。该bcc结构由硅原子显著的短程有序作用所稳定。短程有序bcc结构与长程有序立方B2结构之间的混溶隙随温度升高而缩小，且在6000 K以上该转变变为连续转变。我们发现，bcc Fe-Si固溶体相比其他结构，能更好地重现内核的低剪切声速、地震各向异性等关键地球物理数据。
英文摘要：
The phase diagram and sound velocities of the Fe-Si binary alloy, crucial for understanding the Earth's core, are determined at inner core boundary pressure with \textit{ab-initio} accuracy through deep-learning-aided hybrid Monte Carlo simulations. A complex phase diagram emerges close to the melting temperature, where a re-entrance of the body-centered cubic (bcc) phase is observed. The bcc structure is stabilized by a pronounced short-range ordering of the Si atoms. The miscibility gap between the short-range ordered bcc structure and the long-range ordered cubic B2 structure shrinks with increasing temperature and the transition becomes continuous above 6000 K. We find that a bcc Fe-Si solid solution reproduces crucial geophysical data such as the low shear sound velocity and the seismic anisotropy of the inner core much better than other structures.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
