A5078884124- Surface and Thin Film Phenomena
- Molecular Junctions and Nanostructures
- Advanced Chemical Physics Studies
- Electron and X-Ray Spectroscopy Techniques
- Semiconductor materials and interfaces
- Quantum and electron transport phenomena
- Magnetic properties of thin films
- Force Microscopy Techniques and Applications
- Surface Chemistry and Catalysis
- Semiconductor materials and devices
- Semiconductor Quantum Structures and Devices
- nanoparticles nucleation surface interactions
- Advanced Materials Characterization Techniques
- Graphene research and applications
- Magnetic and transport properties of perovskites and related materials
- Iron oxide chemistry and applications
- Physics of Superconductivity and Magnetism
- Electronic and Structural Properties of Oxides
- Superconductivity in MgB2 and Alloys
- Chemical and Physical Properties of Materials
- Spectroscopy and Quantum Chemical Studies
- Integrated Circuits and Semiconductor Failure Analysis
- Ion-surface interactions and analysis
- Advanced Condensed Matter Physics
- X-ray Spectroscopy and Fluorescence Analysis
Charles University
2016-2025
Karlsruhe Institute of Technology
2021
Kyushu University
2008-2009
National Institute for Materials Science
2004
Muscovite mica, KAl$_2$(Si$_3$Al)O$_{10}$(OH)$_2$, is a common layered phyllosilicate with perfect cleavage planes. The atomically flat surfaces obtained through cleaving lend themselves to scanning probe techniques atomic resolution and are ideal model minerals clays. Despite the importance of cleaved mica surfaces, several questions remain unresolved. It established that K$^+$ ions decorate surface, but their intrinsic ordering -- unaffected by interaction environment not known. This work...
We have successfully controlled the surface structures of GaAs(001) by changing incident As-molecular species. Under As4 fluxes, c(4 x 4) reconstruction with Ga-As dimers [c(4 4)alpha structure] is obtained, but formation three As-As dimer 4)beta kinetically limited. On other hand, structure change from (2 4), through 4)alpha, to phases observed under As2 fluxes. found that energetically metastable and provides a kinetic pathway for between
Electrons confined within the 2D layer of metals grown on silicon substrates exhibit exotic properties due to strong correlation effects. The properties, such as superconductivity, have been frequently...
The Ga-rich reconstruction of the GaAs(001) surface has been studied. Using scanning tunneling microscopy (STM), we have found existence a well-ordered (4 x 6) under extreme conditions. A structure model, consisting subsurface Ga-Ga dimers and Ga-As dimers, is proposed for surface. This model to be energetically favorable at limit agrees well with our experimental data from STM reflection high-energy electron diffraction.
Self-assembly of organic molecules is a mechanism crucial for design molecular nanodevices. We demonstrate unprecedented control over the self-assembly, which could allow switching and patterning at scales accessible by lithography techniques. use scanning tunneling microscope (STM) to induce reversible 2D-gas-solid phase transition copper phthalocyanine on technologically important silicon surface functionalized metal monolayer. By means ab-initio calculations we show that charge transfer...
Formation of Ag clusters on reconstructed surface $\mathrm{Si}(111)7\ifmmode\times\else\texttimes\fi{}7$ was for the first time observed in real during deposition by means scanning tunneling microscopy. The sequences images taken at room temperature show mechanisms controlling growth and behavior individual adatoms. Obtained data reveal new details attractive interaction between adsorbates occupying adjacent half-unit cells $7\ifmmode\times\else\texttimes\fi{}7$ reconstruction. Time...
Indium atoms are found to interact strongly with the so-called C defects, commonly present on $\mathrm{Si}(100)\text{\ensuremath{-}}2\ifmmode\times\else\texttimes\fi{}1$ surface. As a consequence, In rows growing surface pinned these defects. The reaction of adsorbate defects is studied in detail by ab initio calculations combination scanning tunneling microscopy and spectroscopy. For calculations, we successfully adopted model defect as dissociated water molecule. presence induces state...
Manganese (Mn) adsorption on the $\text{Si}(111)\text{\ensuremath{-}}(7\ifmmode\times\else\texttimes\fi{}7)$ surface followed by annealing at a relatively low temperature of $250\text{ }\ifmmode^\circ\else\textdegree\fi{}\text{C}$ has been studied using scanning tunneling microscopy as well low-energy electron diffraction and Auger-electron spectroscopy. The B20-type structure Mn monosilicide (MnSi) epitaxial ultrathin films is formed with...
In polarizable materials, electronic charge carriers interact with the surrounding ions, leading to quasiparticle behavior. The resulting polarons play a central role in many materials properties including electrical transport, interaction light, surface reactivity, and magnetoresistance, are typically investigated indirectly through these macroscopic characteristics. Here, noncontact atomic force microscopy (nc-AFM) is used directly image Fe
A (1$\ifmmode\times\else\texttimes\fi{}$1) ordered monolayer of thallium atoms on a Si(111) surface has promising potential as material generating spin-polarized electrons [Sakamoto et al., Phys. Rev. Lett. 102, 096805 (2009)]. In an ideal form the is nonmetallic [Lee B 66, 233312 (2002)]. Our scanning-tunneling microscopy and spectroscopy study (1$\ifmmode\times\else\texttimes\fi{}$1)-Tl shows clearly its metallic-like character. On surface, intrinsic regularly shaped defects with increased...
We present the study of GaAs(001) reconstructed surfaces using scanning tunneling microscopy. None previously published structural models $(6\ifmmode\times\else\texttimes\fi{}6)$ and $(4\ifmmode\times\else\texttimes\fi{}6)$ reconstructions can sufficiently describe our observations. In order to explain observed images, As atoms at faulted positions surface Ga-As mixed dimers are proposed be elements included in models. The mechanism transition between...
Influence of reactive defects on size distribution one-dimensional islands is studied by means kinetic Monte Carlo simulations in combination with an analytical approach. Two different models are examined: a model anisotropically diffusing atoms irreversibly aggregating to islands, and reversible close thermal equilibrium which allows atom detachment from during the growth. The can be used simulate island growth group III metals deposited $\text{Si}(100)2\ifmmode\times\else\texttimes\fi{}1$...
Albao et al. [Phys. Rev. B 72, 035426 (2005)] recently reported on a study room temperature growth of Ga Si(100). Monotonically decreasing island size distribution observed by means scanning tunneling microscopy was explained using kinetic Monte Carlo simulations with complex mechanism atom capture. In the simulation, influence $C$-type defects process is not considered. These are commonly Si(100) surfaces and act as initial adsorption sites for deposited metal atoms.
Flat MnSi ultrathin films are epitaxially grown on the Si(111)-(7×7) surface by Mn deposition and subsequent annealing. Low-energy electron diffraction exhbits brightest (3×3)R30° patterns when atoms deposited at ∼3 ML with annealing 250°C. Scanning tunneling microscopy shows that atomically flat MnSi(111) surfaces periodicity formed under above condition, thickness of is ∼7Å. The results support a recent theoretical prediction flat-film formation B20-type Si(111) surface.
We present a combined experimental and theoretical study of submonolayer heteroepitaxial growth Ag on Si(111)-7x7 at temperatures from 420 K to 550 when atoms can easily diffuse the surface reconstruction 7x7 remains stable. STM measurements for coverages 0.05 ML 0.6 show that there is an excess smallest islands (each them fills up just one half-unit cell - HUC) in all stages growth. Formation 2D wetting layer proceeds by continuous nucleation proximity larger (extended over several HUCs)...
Structure and electronic properties of one-dimensional bimetallic In-Sn chains formed by codeposition on a Si(100)-2$\ifmmode\times\else\texttimes\fi{}$1 surface are studied experimentally means scanning tunneling microscopy (STM) spectroscopy theoretically using density-functional theory. The In with small amount Sn allows separation various structures their identification in empty-state STM images. A...
The state of matter in fluid phases, determined by the interactions between particles, can be characterized a pair correlation function (PCF). At nanoscale, PCF has been so far obtained experimentally only means reciprocal-space techniques. We use scanning tunneling microscopy (STM) at room temperature combination with lattice-gas kinetic Monte Carlo (KMC) simulations to study two-dimensional gas highly mobile molecules fluorinated copper phthalocyanine on Si(111)/Tl-(1×1) surface. A...
Adsorption of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) on the Ge(001) surface was studied using scanning tunneling microscopy (STM), spectroscopy (STS), and density-functional theory (DFT) calculations. Only single adsorption configuration PTCDA molecule observed at low coverages room temperature, unlike Si(001) where several configurations were reported. This indicates that molecules more mobile than those Si(001). Atomic structure determined by comparison between STM...