- Growth dynamics and electron reflectivity in ultrathin films of chiral heptahelicene on metal (100) surfaces studied by spin-polarized low energy electron microscopy
Miloš Baljozović, André L. Fernandes Cauduro, Johannes Seibel, Anaïs Mairena, Stéphane Grass, Jérôme Lacour, Andreas K. Schmid, Karl-Heinz Ernst
Phys. Status Solidi B 2021, 258, 2170054
The interaction of electrons with chiral matter gives rise to interesting phenomena such as the chirality-induced spin selectivity. The interdependence of reflectivity of spin-polarized low energy electrons and the absolute handedness of chiral molecules is investigated. First, the growth of homochiral films of helical aromatic hydrocarbons, so-called helicenes, on a Cu(100) surface is studied by means of low-energy electron microscopy and scanning tunneling microscopy in ultrahigh vacuum. As soon as the coverage exceeds one monolayer, double-layer nucleation and growth is favored such that depletion in the first layer occurs. Spatially resolved work function measurements show that second layer patches have a lower work function than first layer areas. Reflectivity spectra of spin-polarized electrons do not show any asymmetry between homochiral films of the enantiomers. Laterally resolved work function measurements do not confirm work function differences like those reported earlier for photoelectron studies of chiral peptide films on ferromagnetic substrates.
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