Interface structure and major element effect of MoSi2(110)/NbSi2(0001)

We performed the first-principles calculations to investigate the interface energies and electronic structures of MoSi2(110)/NbSi2(0001). The effects of major elements Mo and Nb on the interface adhesion of C11b/C40 lamellar structure were also revealed. These calculations suggest that the interface energies of bridge coordinations are relatively small, including Si-Bridge and Nb-Bridge, so the preferred coordination of MoSi2(110)/ NbSi2(0001) is bridge coordination. These separation planes of Si-Bridge and Nb-Bridge coordinations are located on NbSi2 block at MoSi2(110)/NbSi2(0001). It is also found that Mo atom of MoSi2 block and Mo doped in NbSi2 block can segregate at the C11b/C40 interface, while Nb atom of NbSi2 block and Nb doped in MoSi2 block do not segregate at this interface. Mo atom of the interface occupies Nb site (MoNb2) on the NbSi2 block of the interface for the two bridge coordination structures, which leads to the migration of C11b/C40 interface towards NbSi2 block. The interface segregation of Mo generally does not affect the interface adhesion, owing to little effect on charge transfer of MoSi2(110)/NbSi2(0001) interface.