SurfaceScience21 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 93: Poster Session VII: Graphene and beyond I
O 93.1: Poster
Donnerstag, 4. März 2021, 10:30–12:30, P
Electric-field control of a single-atom polar bond — •Maryam Omidian1, Susanne Leitherer2, Nicolas Néel1, Mads Brandbyge2, and Jörg Kröger1 — 1Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany — 2Center of Nanostructured Graphene, Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
The polar chemical bond between a single Au atom terminating the apex of an atomic force microscope tip and a C atom of graphene on SiC(0001) is exposed to an external electric field. For one field orientation the Au-C bond is strong enough to sustain the mechanical load of partially detached graphene, whilst for the opposite orientation the bond breaks easily. Calculations based on density functional theory and nonequilibrium Green’s function methods support the experimental observations by unveiling bond forces that reflect the polar character of the bond. Field-induced charge transfer between the atomic orbitals modifies the polarity of the different electronegative reaction partners and the Au-C bond strength.