Investigations of Pb/Ni(111) 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.