The structural and electronic properties of the rippled NiAl(110) surface are investigated using the all-electron total-energy local-density full-potential linearized augmented-plane-wave method. Surface states are found to have 1.3-eV binding energies at »- in excellent agreement with the Auger spectra data. The geometry of the rippled surface and the optical-phonon frequency at » are determined by means of frozen phonon calculations. In good agreement with recent experiments, we find the rippling to be 0.20 for the composite Ni-Al surface layer with Al displaced outwards relative to the contracted Ni layer. A possible mechanism behind the surface rippling is discussed in terms of charge-transfer effects and electrostatic neutrality. The charge densities and calculated work functions for the relaxed and unrelaxed surfaces are also reported and discussed in relation to this mechanism.
ASJC Scopus subject areas
- Condensed Matter Physics