Structure determination of the platinum (111) crystal face by low-energy-electron diffraction

Abstract

An analysis of low-energy-electron-diffraction intensity profiles from the clean (111) face of platinum is carried out. Calculated intensities are compared with experimental results for specular and nonspecular beams at several angles of incidence for electron energies ≤100 eV. The calculations are based on a $T$-matrix multiple-scattering theory with corrections for lattice vibrations. The scattering from a single atomic site is modeled with a conventional band-structure potential parametrized by six partial-wave phase shifts. The constant inner potential $V_0$ determined from addition of the Fermi energy and a measured value of the work function is found to predict the peak positions accurately. The calculations adequately describe the shapes and relative intensities of primary and secondary features in the experimental intensity profiles. Analysis of the data indicates that the spacing of the topmost atomic layer is the same as the bulk value to within 5% (or approximately 0.1 Å).