First-principles calculations of the surface energy and the magnetism of aPtNi alloy (001) surface

In this study, we present the results of first-principles calculations for the surface energy and the magnetism of a PtNi(001) surface by using a full -potential linearized augmented plane wave method based on the generalized gradient approximation. The surface energies of Pt;Ni(001) with three diffe rent compositions [Pt-100 %, Pt-50 %, and Pt-0 %(Ni-100 %)] at the surface were obtained to be 1.02, 1.23, and 1.28 eV, respectively, from the calcula ted total energies of 3 layers, 5 layers, and layers of PtNi(001). This res ult is consistent with experimental observations of the Pt enrichment at th e PtNi(001) surface. We found that the work functions of Pt-100 %, Pt-50 %, and Pt-0 % surfaces were 6.14, 5.93, and 5.51 eV, respectively. The charge redistribution at the surfaces is also present to give some physical intui tion about on the surface formation.