First-principles study of stability and electronic structural properties of Ag/Au/M (Cu, Ni) interface

This study investigated the interface energy, work of adhesion, and electronic structural properties at the Ag/Au/M(Cu,Ni) interface, employing the first-principles method based on density functional theory. First, the structures of various binary and ternary interfaces were optimized. Subsequently, the total density of states (TDOS), partial density of states (PDOS), charge distribution, and bonding characteristics of these interfaces were investigated. Additionally, the interface energy and work of adhesion of these interfaces were calculated. The results indicated that the Ag/Au/Ni interface exhibited higher stability and bonding strength compared to the Ag/Au/Cu interface. The contribution of the PDOS of atoms at the Ag/Au/M(Cu,Ni) interface to the TDOS can be primarily attributed to d-orbital electrons, while s- and p-orbit electrons had minimal influence on PDOS.Notably, d-d orbital hybridization emerged between the d-orbit electrons in Cu and Ni atoms and those in Ag and Au atoms, enhancing structural stability. Two distinct peaks in the TDOS of Ag/Ni, Au/Ni, and Ag/Au/Ni interfaces appeared near the Fermi level, corresponding to d-d orbital hybridization involving Ni, Ag, and Au atoms. At the Ag/Au/Cu and Ag/Au/Ni interfaces, resonance peaks corresponding to the s and p orbits of Ag and the s and p orbits of Au, as well as the d orbits of Ag and Au, indicated the presence of a relatively strong metallic bond between Ag and Au atoms. Furthermore, the Ag/Ni and Au/Ni systems exhibited greater average electron transfer compared to the Ag/Cu and Au/Cu systems. Moreover, atomic bond lengths at the Ag/Au/Ni interface were significantly less than those at the Ag/Au/Cu interface, indicating higher stability of the Ag/Au/Ni interface compared to the Ag/Au/Cu interface.