Calculation of surface energy of metals and alloys by the electron density functional method

The surface energy values of (100), (110), (111) surfaces in Ni, AI and ordered alloys NiAl and NisAl have been calculated within the framework of methodology based upon the electron density functional method. The results of calculations are in good agreement with the known for pure metals experimental data and in case of Ni₃Al alloy. There is also a good agreement with the results obtained by calculation using the embedded atom method. The investigation has been carried out in this work to show that the surface energy σ of alloys can not be interpreted as an averaged concentration σ of pure metals. For NiAl, the obtained results reveal considerable distinctions in anisotropy of σ in comparison to the anisotropy of surface energy in pure metals.