We report here the reversibility and bistability of the switching behavior in an azobenzene derivative induced by the bias applied by a scanning-tunneling microscopy (STM) tip, at low temperature and…
Submolecular-scale control of phototautomerization
Optically activated reactions initiate biological processes such as photosynthesis or vision, but can also control polymerization, catalysis or energy conversion. Methods relying on the manipulation of light at macroscopic and…
Stereoisomeric selection upon adsorption: A structural and optical study of curcuminoid derivatives on ultrathin films of KCl on Au(111) and on bulk KCl(001)
We present a combined scanning tunneling microscopy (STM), noncontact atomic force microscopy (nc- AFM), and differential reflectance spectroscopy (DRS) study aiming at the characterization of the relationship between structural and…
Dual-heterodyne Kelvin probe force microscopy
We present a new open-loop implementation of Kelvin probe force microscopy (KPFM) that provides access to the Fourier spectrum of the time-periodic surface electrostatic potential generated under optical (or electrical)…
Highly Conductive Tungsten Suboxide Nanotubes.
We demonstrate a high electron conductivity (>100 S/cm and up to 1000 S/cm) of tungsten suboxide W(18)O(52.4-52.9) (or equivalently WO(2.91-2.94)) nanotubes (2-3 nm in diameter, ∼ µm long). The conductivity…
Observation of Kekulé vortices induced in graphene by hydrogen adatoms
Fractional charges are one of the wonders of the fractional quantum Hall effect. Fractional excitations are also anticipated in two-dimensional crystals of non-interacting electrons under time-reversal symmetry, as bound states…
Manipulation of the Magnetic State of a Porphyrin-Based Molecule on Gold: From Kondo to Quantum Nanomagnet via the Charge Fluctuation Regime
By moving individual Fe-Porphyrin-based molecules with the tip of Scanning Tunneling Microscope in the vicinity of a Br-atom containing elbow of the herringbone-reconstructed Au(111), we reversibly and continuously control their…
Characterizing the Water-Forming Reaction on Graphite- and Ceria-Supported Palladium Nanoparticles and Nanoislands by the Work Function
The water-forming reaction (WFR) between oxygen and hydrogen on metal surfaces is an important reaction in heterogeneous catalysis. Related research mostly focused on crystalline metal surfaces and thick films; however,…
A simple KPFM-based approach for electrostatic- free topographic measurements: the case of MoS2 on SiO2
A simple implementation of Kelvin probe force microscopy (KPFM) is reported that enables recording topographic images in the absence of any component of the electrostatic force (including the static term).…
Hidden surface photovoltages revealed by pump probe KPFM
We use pump-probe Kelvin probe force microscopy (pp-KPFM) in combination with non-contact atomic force microscopy (nc-AFM) under ultrahigh vacuum, to investigate the nature of the light-induced surface potential dynamics in…