地核温压下“铁/镍-卤素”体系的相图与性质

项目名称： 地核温压下“铁/镍-卤素”体系的相图与性质

项目编号： No.11474128

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 王晖

作者单位： 吉林大学

项目金额： 88万元

中文摘要： 近年来备受关注的地球初始地幔卤素亏损现象蕴涵着许多重要的凝聚态物理问题。由于该现象或源于卤素与地核主要成分铁与镍反应生成了新物质，地核温压下铁/镍-卤素体系的相图和性质可能是理解该现象的关键，但相关研究还是空白，亟待展开。本项目拟采用第一性原理方法，结合晶体结构预测、杂化自由能计算等方法，研究地核温压下铁/镍-卤素系统的相图与性质：探索铁/镍-卤素系统的稳定化合物与固溶体结构，稳定化学配比，构筑高温高压相图；研究稳定化学配比化合物或固溶体的高温高压状态方程、相变机理、波速等物理性质；揭示原子电荷转移、化学成键等化学性质；探索压力、温度、化学组分与稳定化合物或固溶体的物理与化学性质之间的关联。本项目的实施能弥补铁/镍-卤素体系高温高压相图与性质的缺失，为理解地球初始地幔卤素亏损现象提供理论依据，为其它地核主要-次要/微量元素系统研究提供新思路。

中文关键词： “铁/镍-卤素”体系；高温高压；相图预测；相变机理；第一性原理

英文摘要： Recently, the missing halogen paradox and the underlying condensded-mater physics problems have attracted a lot of attentions. Since the mising halogens might have been stored in earth's core as alloys/componds formed from reactions of iron/nickel with them, the phase diagrams and physical/chemical proporties of Fe/Ni-Halogens system at earth's core conditions may paly a key role in understanding the missing halogen paradox. However, those important information are still unavialable now. Here, we proposed a research program to study the phase diagrams and properties of the Fe/Ni-Halogens binaries by first-principles methods in combination with crystal structue prediction and hybride free enegery methods. More specifically, we will perform structure predictions for those binaries at various stoichiometrics and build the high-pressure/temperature phase digrams; investigate the equation of states, mechanism of phase transition, and vilocity of the stable binaries; study the charge transfer and chemical bondings; reveal the relastionship between pressure/temperature/stoichiometic and the physical/chemical properties. We anticipate the results are helpful in understanding the missing helogen paradox.

英文关键词： Fe/Ni-Halogen binaries;High temperature and high pressure;Phase diagram prediction;Mechanism of phase transition;First Principles