Structural stability of ternary D8m–Ti5Sb2X (X=Al, Ga, In, Si, Ge, Sn) compounds

Abstract The crystal and electronic structures of Ti 5 Sb 2 X (X=Al, Ga, In, Si, Ge, Sn) ternary compounds in the Nb 5 Sn 2 Si-type structure (ternary-D8 m ) have been investigated by means of first principles calculations. The calculated structural parameters are in good agreement with the experimental data. The total electronic densities of states as well as the Bader charges of the atoms have been computed. Both electronic and size effects allow to explain the stability of the Ti 5 Sb 2 X (X=Al, Ga, In, Si, Ge, Sn) ternary compounds in the ternary D8 m structure. The enthalpies of formation of the ternary D8 m compounds have been obtained. The off-stoichiometry domains of D8 m –Ti 5 Sb 2 Ga and D8 m –Ti 5 Sb 2 Si are discussed.