Search results for "Scanning Tunneling Microscope"
showing 10 items of 127 documents
Atomic Structure and Mechanical Behaviour of Passive Film Formed on Stainless Steels
1995
On-Surfaces Synthesis on Insulating Substrates
2016
On-surface synthesis has attracted great attention in recent years due to its promising potential for creating functional structures on surfaces. An important aspect of on-surface synthesis is the capability to arrive at covalently linked thermally stable structures that offer the possibility for application even in harsh environments outside ultra-high vacuum conditions. Additionally, covalent linking allows for fabricating conjugated structures with superior electron transport properties. Especially, the latter is of tremendous interest when considering future applications in the field of molecular electronics. Having molecular electronics applications in mind explains the need for decoup…
Near-field study with a photon scanning tunneling microscope: Comparison between dielectric nanostructure and metallic nanostructure
2007
Abstract Scanning near-field optical microscopy (SNOM) integrates standard optical methods with scanning probe microscopy (SPM) techniques allowing to collect optical information with resolution well beyond the diffraction limit. We study the influence on image formation of several parameters in scanning near-field microscopy. The numerical calculations have been carried out using the differential method. We investigate a 2D-PSTM configuration with a dielectric rectangular object. We will focus on the collection type SNOM in a constant height scanning mode. Various oscillation patterns are observed from both sides of the nanostructure, which we interpret as interference between the diffract…
Near-field observation of evanescent light wave coupling in subwavelength optical waveguides
2002
International audience; We report the observation, in the range of visible frequencies, of the coupling of light into integrated waveguides of subwavelength cross-sections together with a subwavelength detection at the output, of such guides. Coupling in is produced by controlling the focusing of a laser beam totally reflected at the surface of the sample. Several tens of micrometres long dielectric ridges have been efficiently excited with this technique. The phenomenon is observed in direct space by a Photon Scanning Tunneling Microscope which also allows to test the principle of detection in a subwavelength volume.
Addressing and imaging high optical index dielectric ridges in the optical near field
2001
Experimental observation of light coupling between ${\mathrm{TiO}}_{2}$ integrated waveguides of subwavelength cross section and pure three-dimensional evanescent light fields is reported. This near-field optical phenomenon is produced by controlling the location of the focusing of a laser beam totally reflected at the surface of the sample. The phenomenon is observed in direct space with a photon scanning tunneling microscope. Dielectric ridges several tens of micrometers long have been efficiently excited with this technique. Upon excitation, the extremities of the linear dielectric wires display intense light spots localized both inside and around the ridge. For ridge lengths up to $30\e…
Real-space imaging with pattern recognition of a ligand-protected Ag374 nanocluster at sub-molecular resolution
2018
High-resolution real-space imaging of nanoparticle surfaces is desirable for better understanding of surface composition and morphology, molecular interactions at the surface, and nanoparticle chemical functionality in its environment. However, achieving molecular or sub-molecular resolution has proven to be very challenging, due to highly curved nanoparticle surfaces and often insufficient knowledge of the monolayer composition. Here, we demonstrate sub-molecular resolution in scanning tunneling microscopy imaging of thiol monolayer of a 5 nm nanoparticle Ag374 protected by tert-butyl benzene thiol. The experimental data is confirmed by comparisons through a pattern recognition algorithm t…
Polymorphism of Two-Dimensional Halogen Bonded Supramolecular Networks on a Graphene/Iridium(111) Surface
2017
bibtex: ISI:000393443200020 bibtex\location:'1155 16TH ST, NW, WASHINGTON, DC 20036 USA',publisher:'AMER CHEMICAL SOC',type:'Article',affiliation:'Sicot, M (Reprint Author), Univ Lorraine, CNRS, Inst Jean Lamour, UMR 7198, BP 70239, F-54506 Vandoeuvre Les Nancy, France. Sicot, Muriel; Kierren, Bertrand; Fagot-Revurat, Yannick; Moreau, Luc; Granet, Julien; Malterre, Daniel, Univ Lorraine, CNRS, Inst Jean Lamour, UMR 7198, BP 70239, F-54506 Vandoeuvre Les Nancy, France. Tristant, Damien; Gerber, Iann C., Univ Toulouse, CNRS, INSA, LPCNO,UPS, 135 Ave Rangueil, F-31077 Toulouse, France. Tristant, Damien, Univ Toulouse, CNRS, CEMES, UPR 8011, 29 Rue Jeanne Marvig,BP 94347, F-31055 Toulouse, Fran…
Graphene and graphene oxide on Ir(111) are transparent to wetting but not to icing
2021
Anti-icing coatings reduce the freezing onset temperature for water by changing the chemical and physical environment at the water-substrate interface to prevent ice nucleation and growth. Graphene oxide has several attributes that make it attractive as an anti-icing coating and it has been theoretically predicted that graphene oxide has a lower freezing onset temperature than pristine graphene. Here, we test this hypothesis using carefully prepared, well-characterized graphene oxide substrates. We compare the water contact angle for graphene and graphene oxide coatings, both prepared on iridium(111) surfaces. The results show both materials to be transparent to wetting, but indicate a lowe…
Tuning the hole injection barrier in the intermolecular charge-transfer compoundDTBDT-F4TCNQ at metal interfaces
2014
Molecular monolayers of the charge-transfer salt dithienobenzodithiophene-tetrafluorotetracyanoquinodimethane (DTBDT-F${}_{4}$TCNQ) have been deposited on C(R$15\ifmmode\times\else\texttimes\fi{}3$)/W(110), Co/W(110), and hcp Co(0001) using molecular beam epitaxy in an ultrahigh vacuum. The integrity of the deposited molecules has been confirmed by scanning tunneling microscopy. Scanning tunneling spectroscopy has been used to determine the energetic positions of the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbital of acceptor and donor in the pure and in the mixed phase. The mixed charge transfer phase exhibits a new HOMO close to the Fermi edge depicting a charge tra…
Deformation-Free Topography from Combined Scanning Force and Tunnelling Experiments
1993
We show that by measuring force and stiffness on a constant-current scanning tunnelling microscopy (STM) contour a deformation-free topography can be extracted. With reference to mono- and bicomponent self-assembled monolayers, we find that the characteristic depression pattern and the protrusions on a multicomponent film found in STM are to a great extent due to electronic effects.