Impurity doping into Mg2Sn: A first-principles study

We studied the formation energy and atomic structure of impurities in Mg2Sn using first-principles plane-wave total energy calculations. Twenty elements, namely H, Li, Na, K, Rb, Sc, Y, La, Cu, Ag, Au, B, Al, Ga, In, N, P, As, Sb, and Bi, were selected as the impurity species. We considered structural relaxation of the atoms within the second nearest neighbors of the impurity atom in the 48-atom supercell. The results of the formation energy calculations suggested that Sc, Y, La, P, As, Sb, and Bi are good n-type dopants whereas Li and Na are good p-type dopants. The electrical properties of Li-, Na-, and Ga-doped Mg2Sn and La-doped Mg2(Si, Sn) composites reported previously can be explained by the low formation energies of Li, Na, Ga, and La in Mg2Sn.