LaS/CeS与γ-Fe异相界面性质的第一性原理计算  

First-Principles Calculations of Interface Characteristics Between LaS/CeS andγ-Fe

作　　者：周印 计云萍[1] 齐建波[1] 辛浩浩 李一鸣[1] Zhou Yin;Ji Yunping;Qi Jianbo;Xin Haohao;Li Yiming(School of Materials and Metallurgy(School of Rare Earth),Inner Mongolia University of Science and Technology,Baotou 014010,China)

机构地区：[1]内蒙古科技大学材料与冶金学院(稀土学院),内蒙古包头014010

出　　处：《稀有金属材料与工程》2022年第12期4551-4560,共10页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51761034)。

摘　　要：为了探讨LaS/CeS与γ-Fe两相之间的异相界面性质,采用边-边匹配(E2EM)模型计算了LaS/CeS与γ-Fe两相之间晶体学上的原子匹配情况,基于晶体学计算结果,采用基于密度泛函理论的第一性原理,从原子尺度计算了LaS/CeS与γ-Fe之间的界面结合性质与界面能。晶体学计算表明,LaS/CeS与γ-Fe之间沿匹配列的原子间距错配度最小值为10.63%/10.52%,密排面间距错配度最小值为2.04%/3.32%;LaS与γ-Fe之间粗略的位向关系为:[110]LaS//[100]γ-Fe&(222)Las//(002)γ-Fe和[100]Las//[101]γ-Fe&(022)LaS//(111)γ-Fe;CeS与γ-Fe之间粗略的位向关系为:[110]LaS//[100]γ-Fe&(222)Las//(002)γ-Fe和[100]Las//[101]γ-Fe&(022)LaS//(111)γ-Fe。基于预测的晶体学位向关系,采用相干界面近似构建了6种不同终端界面模型,第一性原理计算表明,LaS/CeS与γ-Fe之间原子匹配错配度最低界面的粘附功为4.78 J·m^(-2)/3.65 J·m^(-2),界面结合强度较高,界面键合以金属键为主。异相界面能计算表明,LaS/CeS与γ-Fe两相之间的原子匹配错配度越小,界面能越低,原子匹配错配度最小时,界面能分别为-0.58 J·m^(-2)/-3.43 J·m^(-2),计算结果能够为LaS/CeS与γ-Fe之间的晶体学匹配提供能量学依据。In order to investigate the heterogeneous-interface characteristics between LaS/CeS andγ-Fe,the atomic matching mismatch between LaS/CeS andγ-Fe from the crystallographic point view was calculated by the edge-to-edge matching(E2EM)model.On the basis of the crystallographic calculations,the first-principle calculation based on the density functional theory was performed to calculate the interfacial bonding characteristics and the interface energy between LaS/CeS andγ-Fe on the atomic scale.The crystallographic calculations indicate that the minimum of the interatomic spacing misfit between LaS/CeS andγ-Fe along the matching direction is 10.63%/10.52%,and the minimum of interplanar spacing mismatch is 2.04%/3.32%.The rough orientation relationships(ORs)are predicted as follows:[110]LaS//[100]γ-Fe&(222)Las//(002)γ-Fe and[100]Las//[101]γ-Fe&(022)LaS//(111)γ-Fe;[110]LaS//[100]γ-Fe&(222)Las//(002)γ-Fe and[100]Las//[101]γ-Fe&(022)LaS//(111)γ-Fe.Based on the predicted ORs,six interface models with different atomic terminations were constructed by the coherent interface approximation.The first-principles calculations show that the adhesion work of the interface between LaS/CeS andγ-Fe with the lowest interatomic mismatch is 4.78 J·m^(-2)/3.65 J·m^(-2),which indicates the larger bonding strength of the interface between LaS/CeS andγ-Fe with the lower interatomic mismatch.The interface bond was dominated by the metal bond.The calculations of interface energy between LaS/CeS andγ-Fe indicate that the smaller the interatomic mismatch is,the lower the interface energy is obtained.The interface energy between LaS/CeS andγ-Fe with the lowest interatomic mismatch is-0.58 J·m^(-2)/-3.43 J·m^(-2).The first-principles calculations can provide the theoretical foundations from the energetics point view for the crystallographic matching between LaS/CeS andγ-Fe.

关 键 词：界面能 电子结构 第一性原理计算 E2EM 

分 类 号：O647[理学—物理化学]