H,O,N,He原子掺杂Al原子的第一性原理研究

First-principles study of H,O,N and He atoms doped into interstitial sites of Al

采用密度泛函理论框架下的第一性原理平面波赝势方法,对Al中分别加入H,O,N和He原子后的晶体状态进行了研究.通过晶体结构和形成能分析比较了杂质原子占据不同位置的难易程度及对晶体稳定性的影响,并从态密度、电荷密度和电荷布居的角度,分析了其电子结构.结果表明:H、O和N原子占据金属Al的四面体间隙最稳定,而He原子主要占据金属Al的八面体间隙. O和N原子与Al原子具有强烈的共价作用,H原子与Al原子存在共价作用但相对较弱,而He原子与Al原子的相互作用以范德华力为主.进一步揭示了四种原子在金属Al中不同行为的电子机制.

The crystal structures of H,N,O and He atoms in Al metal are studied by using the rst-principles calculation method based on the density functional theory.The site occupations of H,O,N and He atoms at the interstitials of the Al lattice are discussed by means of crystal structure and formation energy,and the electronic structures of Al are analyzed by density of states,charge density and charge population.The results show that H,O and N atoms are in the tetrahedral interstice,whereas He atom is more stable in the octahedral interstice of Al metal.In addition,the characteristics of the bonds between O,N and Al atoms are strongly covalent,the covalence of the bond between H and Al atoms is week,whereas the interaction between He and Al atoms is dominated by Van der Walls force,suggesting that there is different behavior of electronic structure for H,O,N and He doped into Al atoms.