9 research outputs found
Quantum size effects in Pb islands on Cu(111): Electronic-structure calculations
The appearance of "magic" heights of Pb islands grown on Cu(111) is studied
by self-consistent electronic structure calculations. The Cu(111) substrate is
modeled with a one-dimensional pseudopotential reproducing the essential
features, i.e. the band gap and the work function, of the Cu band structure in
the [111] direction. Pb islands are presented as stabilized jellium overlayers.
The experimental eigenenergies of the quantum well states confined in the Pb
overlayer are well reproduced. The total energy oscillates as a continuous
function of the overlayer thickness reflecting the electronic shell structure.
The energies for completed Pb monolayers show a modulated oscillatory pattern
reminiscent of the super-shell structure of clusters and nanowires. The energy
minima correlate remarkably well with the measured most probable heights of Pb
islands. The proper modeling of the substrate is crucial to set the
quantitative agreement.Comment: 4 pages, 4 figures. Submitte