Atomic structure, stability and electronic properties of S(Al2CuMg)/Al interface: A first-principles study

Interfacial models of Al2CuMg/Al were investigated by first-principles calculations based on density functional theory. Two types of Al2CuMg(001)/Al(021) interface structures were investigated in consideration of two different terminations for Al2CuMg(001) surface (Al-terminated and CuMg-terminated). The interaction of interfaces was analyzed by the optimized atomic structures. The ideal work of adhesion (Wad) of the Al2CuMg(001)/Al(021) interfaces was also calculated. The results show that the interface model with CuMg-terminated is more stable than that of Al-terminated. It is also demonstrated from the values of interfacial energy (γint) that the CuMg-terminated interface is more thermodynamically stable. The calculated electronic properties, including charge density distribution and density of states, reveal that there is a significant hybridization among the interfacial Cu 3d, Mg 3p and Al 3p states. It is the main reason why CuMg-terminated interface is more stable.