高春来,高坤元,熊湘沅,黄晖,文胜平,吴晓蓝,聂祚仁.有序结构Al3Er对应的Er在Al中固溶度的第一性原理计算[J].稀有金属材料与工程,2020,49(8):2738~2745.[高春来,Gao Kunyuan,Xiong Xiangyuan,Huang hui,Wen Shengping,Wu Xiaolan,Nie Zuoren.The study of the solubility of Er in Al from the first-principles[J].Rare Metal Materials and Engineering,2020,49(8):2738~2745.]
有序结构Al3Er对应的Er在Al中固溶度的第一性原理计算
投稿时间:2019-07-29  修订日期:2019-10-14
中文关键词:  第一性原理  Al3Er  固溶度曲线  溶解焓  剩余熵
基金项目:
中文摘要:
      采用基于密度泛函理论的第一性原理计算方法获得了hR20、cP4和hP8结构Al3Er对应的Er的固溶度曲线。同时,在计算中利用了对Er的4f电子分别视为核心电子和价电子的不同赝势。通过对不同4f电子近似下获得的溶解焓的加权平均,获得的cP4结构Al3Er对应的Er的固溶度曲线更加接近实验测量结果。计算获得的hR20、cP4和hP8结构Al3Er对应的Er的固溶度量值近似相等,远小于hP8结构对应的固溶度值。结合结构分析显示,cP4结构比hR20结构简单是造成cP4结构Al3Er更易从固溶体中析出的主要原因。
The study of the solubility of Er in Al from the first-principles
英文关键词:First-principles  Al-Er alloys  Solubility  Solution enthalpy  Excess entropy
英文摘要:
      The solubility curves of Er in Al-Er alloys were investigated by means of first principles calculations based on the density functional theory. The solution energies of Er atoms in these Al-Er alloys were calculated by using the “Frozen core” approximation and “Standard potential” approximation for the 4f electrons, respectively. The calculated results showed that the solution energies of hR20, cP4 and hP8-Al3Er were -1.003 and -0.767 eV/Er atom, -0.989 and -0.787 eV/Er atom, -0.967 and -0.713 eV/Er atom, respectively, obtained from the two approximations. The lattice dynamics calculation showed that the excess enthalpies of hR20, cP4 and hP8-Al3Er were 3.301, 3.226 and 3.309 kB/Er atom. The simulated solubility curves were obtained by combining the lattice dynamics values and the weighted average of the solution energy values. The calculated solubility curves of cP4-Al3Er were consistent with the experimental values, which indicates that the 4f electrons play a very important role. In addition, the solubility curve of cP4-Al3Er was very close to that of the hR20-Al3Er, but lower than that of hP8-Al3Er at the same temperature. The chemical driving forces corresponding to the solubility curves of hR20 and cP4-Al3Er were also close to each other, but larger than that of the hP8-Al3Er. Due to the smaller interfacial energy in Al matrix of cP4-Al3Er than that of hR20-Al3Er, it could be deduced that the cP4-Al3Er precipitation was the first in priority order, which was consistent with the experimental observations.
作者单位E-mail
高春来 材料科学与工程学院 gclai@126.com 
高坤元 材料科学与工程学院  
熊湘沅 材料科学与工程学院  
黄晖 材料科学与工程学院  
文胜平 材料科学与工程学院  
吴晓蓝 材料科学与工程学院  
聂祚仁 材料科学与工程学院  
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