Adsorbate induced Reconstruction of Ni(100)

We have carried out a systematic lattice dynamical study of the c(2x2) overlayer of oxygen, sulfur and carbon (nitrogen) on Ni (100). The model consists of nearest neighbour interactions between all atoms and an additional (attractive) interaction between the adsorbate atoms and the second neighbour substrate atom directly below, which consequently introduces internal stresses. We show that the relative strength of the internal stress and the coupling between the first and second layer nickel atoms determine whether the Ni (100) surface will reconstruct. The presence of the attractive force between the adsorbate atoms and the second layer nickel atoms allows us to explain the observed anomaly in the dispersion of the Rayleigh wave for the oxygen overlayer on Ni (100) and leads to a natural explanation for the reconstruction pattern observed in the presence of the carbon and nitrogen overlayers via softening of a substrate phonon. © 1986