The structures, stability, mechanical properties and electronic properties of X (X=Nb, Ge, Ni) doped Al2Cu: a first-principle study

Abstract

The structures, stability mechanical properties and electronic properties of X (X=Nb, Ge, Ni) doped Al2Cu were studied by first-principles. The results show that the stable structures can be formed are Al64Cu32, Al63Cu32Nb, Al64Cu31Nb, Al63Cu32Ge, Al63Cu32Ni, Al64Cu31Ni. Doping X improved the stiffness of the Al2Cu. Al64Cu31Ni has the largest stiffness and Al64Cu31Nb has the smallest stiffness. However, the ductility of Al2Cu is reduced after doping with X. Doping X can greatly reduce the anisotropy of the whole system and the {100}, {010} surface. Among them, Al63Cu32Ge has the lowest degree of anisotropy, and Al64Cu31Ni has the highest degree of anisotropy. Doping Nb cause strong orbital hybridization between Al (3s) and Nb (4d), doping Ni causes strong orbital hybridization between Al (3s) and Ni (3d). The bonding strength and stability of Al2Cu will be significantly changed by these two elements.