Investigations of Pb/Ni(1Â 1Â 1) using incident beam electron diffraction

The crystalline structure of ultrathin Pb layers deposited on the Ni(1 1 1) surface in ultrahigh vacuum was investigated with the use of directional elastic peak electron spectroscopy (DEPES). Experimental DEPES data recorded for the primary electron beam energies in the range 1.0-1.9 keV were compared with theoretical profiles obtained with the use of single scattering cluster (SSC) calculations for clean and covered Ni(1 1 1). Similar intensity maxima reflecting the crystalline structure of the Ni(1 1 1) sample were observed on experimental and theoretical profiles. Results obtained after deposition of 10 ML of Pb on Ni(1 1 1) at the substrate temperature T = 150 K exhibit intensity maxima corresponding to two mutually rotated Pb(1 1 1) domains. The populations of two possible Pb domains were determined by an R-factor analysis. The growth of one domain was found to be preferred, which can be rationalised by the miscut of the Ni(1 1 1) sample and the resulting step orientation.