First-principles simulations of the interface adhesion and wettability: Cu(111)/TiC(111) versus Cu(111)/WC(0001)
Yuan Fang, Mao Wu, Shi-nan Ci, Qing Liu, Xinpeng Zhao, Ping Qian, Xuanhui Qu
Abstract
The adhesion and wettability of Cu(111)/TiC(111) and Cu(111)/WC(0001) interface system were studied by first-principles simulations comparatively. It is found that the C terminal is more active than metal (Ti, W) terminal in both TiC(111) and WC(111) due to the high surface energy, and thereby the C terminal is more likely to form the interface with Cu. The hybridization between the Cu d and C p orbital leads to a strong Cu-C bonding at the interface, which makes the W sep of C terminal interface is higher than the metal terminal interface. In addition, the W-C covalent bond weakens the Cu-C electronic interaction at the Cu/WC interface, leading to a lower W sep of Cu(111)/WC(0001) comparing to the Cu(111)/TiC(111). The wetting angle of metal/carbide can be calculated by the combining of the surface energy and interface energy, and the C-terminated Cu(111)/TiC(111) system has the lowest wetting angle. The DOS results demonstrated that the bonding strength between metal and carbide rely not only on the types of carbide , but also on the electronic structure of metal.