Effect of Impurities on the Oxygen Adsorption Properties on the NiTi(110) Surface

The effect of 3d–5d elements on the oxygen adsorption energy on the NiTi(110) surface has been studied by the projector augmented-waves method within density functional theory. It is shown that almost all elements, except for a few elements of the end of d periods, lead to an increase in the adsorption energy if they substitute for nickel. On the contrary, the substitutional impurities in the titanium sublattice lower this energy. Based on the analysis of the electronic characteristics of the surface with impurities, it has been found that an increase/decrease in the oxygen adsorption energy on NiTi(110) correlates with a change in the ionic contribution to the mechanism of oxygen bonding with the surface.