First-principles calculation of hydrogen adsorption and diffusion on Mn-doped Mg2Ni (010) surfaces

Effects of Mn doping on the hydrogen adsorption and diffusion on the Mg2Ni (010) surface are studied using first-principles density functional theory. The results show that the Mg2Ni (010) surface becomes more uneven and the thermodynamical stability of Mg2Ni (010) system is lowered after Mn doping. Analysis of the hydrogen adsorption energies on the pure and Mn-doped Mg2Ni (010) surfaces shows that Mn-doped Mg2Ni (010) surface has more sites for hydrogen to adsorb stably. Further calculation of the hydrogen diffusion indicates that the substitution of Mg with Mn lowers the energy barrier for hydrogen to diffuse from the (010) surface to the subsurface.