Figure 1: DyPc2 on Cu(001).
From: Sub-molecular modulation of a 4f driven Kondo resonance by surface-induced asymmetry
(a) STM topographic image (18.6 × 18.6 nm; Vset=−0.1 V, Iset=0.1 nA) of DyPc2 molecules, which are observed to bind at two angles, as marked with a dotted white line. (b) Schematic of the binding of molecules to the surface, showing the lower (dark green) and upper (light green) Pc ligands, with the centre of the molecule placed over the hollow site in the Cu(001) surface25; the central Dy atom is shown. Pc molecules have been observed to bind at ±18°. For an assumed rotation of 45°, the top Pc ring will appear at ∓27°, which is approximately the observed angle of the molecules. (c) High-voltage spectroscopy (Vset=−1.5 V, Iset=0.1 nA) acquired over the ligand (black) and the centre (red) of a DyPc2 molecule (positions shown in inset on an STM topographic image, 3.5 × 3.5 nm, Vset=−0.2 V, Iset=0.1 nA). (d) Calculated partial density of states (PDOS) of π states in the top (black) and bottom ligand (grey), and Dy d- (red) and f-states (dark blue). The lower ligand is strongly hybridized with the surface and also weakly hybridized to the top ring.
