Atomic relaxation, stability and electronic properties of Mg2Sn (100) surfaces from ab-initio calculations

Mg2Sn (100) surfaces were investigated using ab-initio method based on density functional theory in order to explore the surface properties. It is found that both the eleven-layers for Mg-termination surfaces and the nine-layers for Sn-termination surfaces are all converged very well. The effects of relaxation mainly occurred within the three outermost atomic layers for both Mg and Sn terminations during the surface relaxation. Mg-termination surfaces are more stable than Sn-termination surfaces according to the analysis of surface energy. The density of states reveals the metallic property of both Mg-termination and Sn-termination surfaces. Covalent bonding exists in Mg2Sn (100) surfaces according to the analysis of partial density of states.