A. Sperl

Demetalation of a Single Organometallic Complex

Single lead-phthalocyanine molecules adsorbed to ultrathin lead islands on Ag(111) are demetalized by transferring the lead atom of the inner macrocycle to the tip of a scanning tunneling microscope. Reactants and products are discriminated by their images and spectroscopic fingerprints.

Unoccupied states of individual silver clusters and chains on Ag(111)

Size-selected silver clusters on Ag(111) were fabricated with the tip of a scanning tunneling microscope. Unoccupied electron resonances give rise to image contrast and spectral features which shift toward the Fermi level with increasing cluster size. Linear assemblies exhibit higher resonance energies than equally sized compact assemblies. Density functional calculations reproduce the observed energies within

Evolution of unoccupied resonance during the synthesis of a silver dimer on Ag(111)

0.6\phantom{\rule{0.3em}{0ex}}\mathrm{eV}

Electronic Superstructure of Lead Phthalocyanine on Lead Islands

and enable an assignment of the resonances to hybridized atomic

Single-atom contacts with a scanning tunnelling microscope

5s

Controlled Metalation of a Single Adsorbed Phthalocyanine

and

Local density of states from constant-current tunneling spectra

5{p}_{z}

Direct observation of conductance fluctuations of a single-atom tunneling contact

orbitals with silver substrate states.

Atom für Atom

Silver dimers were fabricated on Ag(111) by single-atom manipulation using the tip of a cryogenic scanning tunnelling microscope. An unoccupied electronic resonance was observed to shift toward the Fermi level with decreasing atom–atom distance as monitored by spatially resolved scanning tunnelling spectroscopy. Density functional calculations were used to analyse the experimental observations and revealed that the coupling between the adsorbed atoms is predominantly direct rather than indirect via the Ag(111) substrate. While the substrate influence is small owing to the surface-projected sp band gap, the direct interaction is most likely due to the large extension of the p wave functions at the adsorbate atoms contributing to the resonance.

Conductance of Ag atoms and clusters on Ag(111): Spectroscopic and time-resolved data

Lead phthalocyanine (PbPc) deposited on lead islands on Ag(111) forms two-dimensional crystals of densely packed molecules. For particular orientations, the molecular arrays exhibit an electronic superstructure with an extraordinarily large unit cell. The molecules induce a shift of quantum well states, which are confined to the Pb islands. Patterns formed by PbPc on Ag(111) are drastically different.