LEED INVESTIGATION OF THE Pb AND Sb ULTRATHIN LAYERS DEPOSITED ON THE Ni(111) FACE AT T=150–900 K

Abstract

The atomic structure of ultrathin lead and antimony layers deposited on the Ni (111) face in ultrahigh vacuum at a substrate temperature ranging from 150 to 900 K was investigated with the use of low-energy electron diffraction (LEED). LEED patterns corresponding to p(1×1), p(3×3), p(4×4), [Formula: see text] structures and p(1×1), p(2×2), [Formula: see text], [Formula: see text] structures for the adsorption of Pb and Sb, respectively, on the Ni (111) face were observed. Experimental LEED intensity-versus-energy [I(V)] spectra have been collected for the clean Ni (111) and for the [Formula: see text], [Formula: see text], [Formula: see text] structures. The I(V) curves obtained for the clean Ni (111) structure are in good agreement with experimental spectra from the literature.

Quantum size effects on surfaces without a projected bandgap: Pb/Ni(111)

“…We find no indication of the locking-in of the previously reported (3 × 3) structure found at RT [16,18,19], at an in-plane lattice constant of 3.73 Å.…”

“…• surface alloy was also found in the literature, where annealing to T > 850 K followed deposition at RT before alloy formation occurred [16][17][18][19]. A further increase in coverage results in dealloying and the formation of a Pb wetting layer that covers the entire surface above θ Pb/Ni ≈ 0.40 ML.…”

“…Both have been reported on in the literature [16,19] and are illustrated in figures 2(b) and (c). For increasing coverage the main spot intensity moves gradually from the less dense (7 × 7) domains at θ Pb/Ni ≈ 0.51 ML to the denser (4 × 4) domains at θ Pb/Ni ≈ 0.55 ML, as is reflected in the line profiles shown as insets in figure 2(a).…”

Investigations of Pb/Ni(111) using incident beam electron diffraction

“…The initial stage of growth and morphology of ultrathin lead films on Ni(1 1 1) was widely investigated using several techniques during last years [16,[22][23][24][25][26]. Auger electron spectroscopy (AES) measurements indicate the two-dimensional growth of the first Pb monolayer at substrate temperatures between 180 and 480 K [16].…”

Anomalous Decay of Electronically Stabilized Lead Mesas on Ni(111)

“…Beyond a critical thickness the film breaks up even if the interfacial energies predict wetting [2]. This feature is considered of lesser importance for lead films since its lattice parameter is much larger than those of most metal substrates, which often leads to higher order commensurability or even incommensurability [3].…”