The Electronic Structure and Stability of Ti₂SnC/Ag Interface Studied by First-Principles Calculations

In this paper, the electronic properties, the adhesive energy, and the interface energy of the MAX phase Ti2SnC(0001)/Ag(111) interface are systematically investigated using first principles based on density functional theory. Four different terminations of Ti2SnC(0001) are considered, and 16 different Ti2SnC(0001)/Ag(111) interface configurations are obtained by varying the stacking positions of the atoms. After calculating the electronic structure, adhesion work, and interface energy of these interface model interfaces with the same terminal but different atomic positions, it is found that the interface of the same terminal has a very limited effect on the interface bonding of the interface model by changing the stacking order of the interface atomic layer. By comparing the adhesion work and interface energy of 16 interface models, it is found that the HCP2 configuration of C-Ti2SnC(0001)/Ag(111)interface structure has the highest adhesion work and the lowest interface energy. The larger the adhesion work is, the stronger the bonding between the interface atoms is. Meanwhile, the smaller the interface energy (positive value) is, the more stable the interface is. By calculating the electronic structure of the interface, the accuracy of the above results is further verified after analyzing the partial density of states (PDOS) and charge density difference of the interface.