The atomic structure of alloy surfaces: Ni3Al{001}

The determination of the atomic structure of the 001 plane-type surface of Ni3Al by low-energy electron diffraction (LEED) intensity analysis, to correspond to simple truncation of the bulk structure with the Ni-Al mixed layer on top rather than the pure Ni layer, is reported. The first interlayer spacing is found to be equal to the bulk spacing between the 001-type plane. First-principles calculations of the cohesive energies of slabs with two surface terminations indicate that the mixed layer termination is more stable. The LEED intensity spectra intensity versus electron energy which are needed for structure analysis are presented.