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Showing 1 to 20 of 25 for “"STM images"”.
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The electronic structure of galena and hematite surfaces: applications to the interpretations of STM images, XPS spectra and heterogeneous surface reactions
Scanning tunneling microscopy (STM) images and scanning tunneling spectroscopy (STS) spectra of galena (PbS) and hematite (a-Fe203) were calculated using ab-initio methods in order to interpret experimental images and spectra that were taken in previous studies. These calculations have helped to …
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First-principles study of the surfaces of zirconium during early stages of metal oxidation
… 0.55 [angstroms] which should be visible under STM images. Therefore, the periodic relaxation patterns observed on the surface of zirconium at the initial stage in of its oxidation in previous study could be explained by the buckling of the zirconium layer in the oxide coupled with the fact that …
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Reaction of Aqueous Polyoxometalates With Silver and Gold Surfaces
… of Au(111) in the same solutions yielded STM images that did not show evidence of a surface phase. By using a mixture of alpha-PVW11O40 4- and NaP5W30O110 14- in acidic aqueous solution, the terrace size of the surface phase formed on Ag(111) increased and its translational order improved.
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Surface structures of Al-Pd-Mn and Al-Cu-Fe icosahedral quasicrystals
… (LEED) and scanning tunneling microscopy (STM). The set of four surfaces we have investigated, Al-Pd-Mn twofold, threefold, fivefold surfaces and Al-Cu-Fe fivefold surface, allows comparisons between different high-symmetry surfaces within a single alloy, and between different alloy …
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Scanning tunneling microscopy and photoemission spectroscopy studies of clean and adsorbate-covered semiconductor surfaces
"Scanning tunneling microscopy (STM), photoemission spectroscopy, and a variety of other experimental techniques have been used to examine both the initial stages of interface formation between various adsorbates, as well as, reconstructions occurring on the clean surfaces of Si and Ge. The initial …
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Fullerene hydrides and studies toward the syntheses of fulvalenes
… to the tubes. Scanning Tunneling Microscopy (STM) images of the hydrogenated tubes show bright regions around the circumference of the tube that most likely correspond to the region covered by hydrogen. Precursors of two fulvalenes (calicene and triafulvalene) were prepared by multi-step …
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Curvature driven phase separation in mixed ligand coated gold nanoparticles
… here through scanning tunneling microscope (STM) images, as a function of the gold core diameter, which is a measure of the particle's curvature. The packing of OT homoligand nanoparticles is found to have a head-group spacing of 0.54 nm, which differs from that on flat gold (111) surfaces, …
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Microfabrication of silicon tips for scanning probe microscopy
… elevated on a mesa structure. Atomic resolution STM images of graphite are successfully obtained using silicon tips. Subsequently, a co-axial tip was developed for SPELS. SPELS uses an STM tip in field emission mode and then analyses the energy of electrons backscattered. However, the electric …
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Integration of Single -Walled Carbon Nanotubes With Gallium Arsenide(110) and Indium Arsenide(110) Surfaces: A Scanning Tunneling Microscopy Study
… we have used scanning tunneling microscopy (STM) and spectroscopy (STS) to investigate the physical and electronic behavior of single-walled carbon nanotubes (SWNTs) coupled to GaAs(110) and InAs(110) substrates in ultrahigh vacuum (UHV). Both flat and stepped III-V(110) surfaces were …
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Multi-Dimensional Dopant Profiling With Atomic Resolution by Scanning Tunneling Microscopy
… perfect Si(100)2x1:H surface opens the way to STM studies of dopant distributions in Si(100). STM topographic images, dI/dV images and current image tunneling spectroscopy (CITS) were acquired across the lateral PN junctions of Si devices. Two-dimensional dopant (carrier) profiles were …
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Nanoscale Manipulation of Pristine and Functionalized Freestanding Graphene Using Scanning Tunneling Microscopy
… be imaged using a scanning tunneling microscope (STM) and that imaging a flexible 2D surface is fundamentally different from imaging a bulk material due to the attraction between the STM tip and the sample. This attraction can be used to manipulate the graphene sample on atomic and even nanometer …
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The Electronic Structure and Reactivity of Sulfide Surfaces: Combining Atomic-Scale Observations with Theoretical Calculations
… scanning tunneling microscopy and spectroscopy (STM/STS), the electronic structure at atomic sites on these surfaces was directly probed, and chemical insight into the results was provided by ab-initio calculations. Pyrite is the most abundant sulfide at the earth's near surface. Its oxidation …
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The application of scanning tunneling microscopy (STM) and related techniques to the study of organic and biomolecular targets
Scanning tunneling microscopy (STM) has been used to study: (a) Self-assembled monolayers and sub-monolayers of butanethiol adsorbed onto highly uniform Au/mica films, (b) DNA adsorbates on different substrates prepared by different deposition techniques. In addition, surface preparation techniques …
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Thiolate self-assembled monolayers studied with a tuneable infrared low temperature laser driven scanning tunnelling microscope
… scanning tunnelling microscopy/spectroscopy (STM/S) and infrared laser-driven STM (LDSTM). As a tool STM is uniquely able to resolve atoms on a surface. Illuminating an STM with infrared radiation tuned to match modes in the SAM used as the sample provides a unique opportunity to investigate …
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A variable temperature scanning tunneling microscopy study of organizing C60 molecules on nanostructured gold surface
… conditions using variable temperature UHV STM. At room temperature, the C\(_{60}\)/Au interface exhibits rich features observed in the STM images, for instance the lifting of the reconstruction and the appearance of dim molecules in the close-packed C\(_{60}\) overlayer. Furthermore, the …
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Electronic band structure of III-V quantum dots using tight-binding and the k.p approximation
… systems are explored by using cross-sectional STM images of GaSb nanostructures for composition input into a continuum model. Based on a rule-of-mixtures assumption about material properties as a function of composition, the strain field due to lattice mismatch is calculated and used with …
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In-situ TEM study of carbon nanomaterials and thermoelectric nanomaterials
… Atomic resolution scanning tunneling microscopy (STM) images were obtained on the folded layer and the bottom layer of the GNR, which enables clear identification of the chirality for both layers. We have also studied the electronic properties of the GNRs using low temperature scanning tunneling …
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Interfacial and long-range electron transfer at the mineral-microbe interface
… examined with scanning tunneling microscopy (STM). To simulate bacterial metal reduction mediated by proteins in direct contact with mineral surfaces, monolayers of purified decaheme cytochromes from the metal-reducing bacterium Shewanella oneidensis were prepared on Au(111) surfaces. …
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Atomic-level investigation of surface processes governing SiGe wetting layer formation using STM/STS
… scanning tunneling microscopy (STM) is used to study ADCSs, as they only appear in empty-state images. ADCSs are dilute structures comprising type-C addimers that reside in neighboring troughs and extend along all equivalent <130> directions of the surface, giving rise to a …
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Characterization of epitaxial semiconductor films by scanning tunneling microscopy at ambient pressure
… and studied by scanning tunneling microscopy (STM) at ambient pressure. The cleaved surfaces are prepared for imaging by wet chemical treatments. GaAs/AlGaAs and Si/SiGe multilayer structures are imaged with —1 nm resolution. The contrast in the STM images is believed to be topographic in …
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