First-principles investigation on the structures, energies and electronic properties of low-index surfaces of Mg2Pb

In this investigation, we systematically studied the structure, surface energy, and electronic structure of the (001), (110), and (111) surfaces of the Mg2Pb surface through first-principles. The surface relaxation results revealed that the (111) surface experienced the largest relaxation, while the (110) surface undergo the smallest relaxation (0.18%). The calculated surface energy indicates that the energy of the stoichiometric surface has nothing to do with the chemical potential of the corresponding element, and the surface energy of the non-stoichiometric surface has a linear relationship with the chemical formula of the corresponding element. Furthermore, the surface energy calculation results show that the surface energy of the Mg2Pb(111)-Mg and Mg2Pb(110)-MgPb surfaces is the lowest, indicating that the Mg2Pb(111)-Mg and Mg2Pb(110)-MgPb surfaces are the most stable. The electronic structure of the stoichiometric surface is similar to the bulk Mg2Pb, while the electronic structure of the nonstoichiometric surface has a significant effect on surface relaxation.