Theory and theoretical simulation methods of Scanning Probe Microscopy including Scanning Tunneling Microscopy, and various kinds of Atomic Force Microscopy are reviewed with recent results. The topics introduced here are the method for the STM Simulation, effect of the dissipation on the tunneling current as well as the method for the theoretical simulation of the Atomic Force Microscopy in water. We presented two methods based on the classical molecular dynamics and 3D Reference Interaction Site Method (3D-RISM). Some remarkable properties of the 3D force map of mica in water and the effect of the local charging of the sample on the water mediated force are discussed.
The new and distinct surfaces provide an opportunity for the development of efficient atomically/molecularly-organized catalysts. The key factors of regulation and design of catalyst surfaces are structure, composition, oxidation state, distribution, morphology, polarity, etc. which should be organized at the surfaces. In the development of novel catalyst surfaces, new concepts and strategies regarding composition or structure are conceived, where in situ characterizations by surface science are inevitably important for understanding the origin and mechanism of the tremendous catalysis of surfaces. These key issues can be derived from single crystal surfaces and designed surfaces experimentally and theoretically.
Synchrotron radiation surface research has shown drastic progress in these twenty years mainly owing to higher brilliance of synchrotron radiation sources and higher sensitivity and/or resolution of detectors. We have developed an in situ analysis system combined with a thin film growth chamber for advance device applications, and have used this system as a nano-space laboratory for analyzing surface/interface electronic structures.
Only after the invention of the atomic force microscope (AFM), measurement of single molecule mechanical properties of DNA and proteins became possible. Until then, single molecule mechanical properties were of theoretical interest but difficult to be measured. The rigidity, toughness of individual protein molecules or the strength of protein-protein interactions has become a popular subject since then. In this article, 1) the single molecule mechanics of α-helical polypeptide, 2) force spectroscopy of pulling membrane proteins from red blood cell surface, and 3) a new method of hole creation with controlled positioning and size on the live cell surface are reviewed as examples of recent development from our laboratory. By exploiting more diversified uses of the probe modification, the AFM based technology will be brought to a stage with many more routine applications in biological field.
Of the phenomena which occur at the interface between a solid and a liquid, common examples include the deposition and corrosion of metals, the charging and discharging of storage batteries, and the wet processing of semiconductor devices. Developments in STM operated at solid-liquid interfaces led to its valuation as arguably the premier technique for atomic-level surface structural investigations of chemical processes taking place at solid-liquid interfaces. The present article describes a brief current status of in situ STM.
Hexagonal BN (h-BN) is graphite-like sp2-bonded crystal phase, which is the most stable among crystalline BN phases, and has a potential for optical device applications in the deep ultraviolet spectral region. Crystalline phase of BN film grown on a foreign substrate is turbostratic BN (t-BN) or mixed phase with t-BN, h-BN and cubic BN due to the large lattice mismatch and its various crystalline BN phases. Therefore, control of the crystalline phase in the BN film is challenging for single-phase BN growth. Here, we demonstrate that single-phase h-BN epitaxial films can be grown on nearly lattice-matched substrates by optimizing growth conditions during metalorganic vapor phase epitaxy and molecular beam epitaxy (MBE). We also investigate the ultraviolet luminescence properties of near band-gap emission in the h-BN epitaxial films grown by MBE.
The author discuss the effects of the alkylchain length, kinds of molecules and multilayers upon the tribological properties of organosulfur self-assembled monolayers (SAMs) on Au surfaces using a conventional pin-on-plate method. The tribological properties of SAMs covalently bonded to Si and alkylsilane SAM were investigated to examine the effect of the head groups upon the tribological properties. For the alkylchian length effect, the SAMs with longer alkylchains showed lower and more stable friction coefficients than those with shorter alkylchains. For the effect of the kinds of molecules, the SAMs with phenyl rings and those with alkylchains had similar tribological behavior. However, the SAMs with phenyl rings had higher wear resistance than those with alkylchins. For the tribological properties of multilayers, the double layer with outer most layers of methyl groups showed lower friction coefficients than monolayers. The appropriately loosely packed bound molecules of the topmost layer in the double layers probably led to the decreased friction. For the effect of head group, the SAMs with Si-C bond and long alkylchains had low friction coefficients and high wear resistivity.