Application of carbon nanotube electodes with nano-scale gap and its fabrication method are reviewed. Contact resistance in nano-scale molecular electronics or organic electronics is serious issue to be solved for operation of future electronics. So far, conventional metal electrodes are widely used for the nano-device researches. Here, we proposed to use the carbon nanotube, and a pentacene nanocrystal transistor with carbon nanotube electrodes as a nanosize source and drain was fabricated. In the device fabrication, the evaporated pentacene selectively grew around the nanotube electrodes. This may be caused by the common nanounit combination of the carbon six-membered ring contained in the pentacene and the nanotube. The nanotransistor showed controllable transistor operation at room temperature and Coulomb blockade oscillations at 4.2 K in gate voltage characteristics.

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  We would like to share our recent results from a research on the single electron tunneling effect in a double-barrier tunneling junction (DBTJ) structure. Single Au nanoparticles were trapped in a nanogap electrodes, whose gap size was precisely controlled using a combination of electron beam lithography and molecular ruler technique. Here, we introduce how the novel combination technique was utilized to obtain the nanogap electrode. We also introduce the size effect of Au particles on the single electron tunneling behavior as a Coulomb island. Finally, we introduce the relation between the geometrical and electrical properties of the DBTJ.

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  We have developed multiple-scanning-probe microscope (MPSPM) to measure electrical transport properties of nanoscale conductors. Versatility of MPSPM are shown through the measurements of nanowires (NWs), in which two independently driven probes need to make nanosized contact to the measuring object and obtain its image with the probes themselves. Electrical measurements have been performed on metal-silicide NWs epitaxially formed on Si(001) substrate. Interesting phenomena unique to nanoconductors, such as large resistance induced by inelastic surface scattering, are observed. Tungsten-suboxide nanorods epitaxially grown on electrochemically-etched tungsten tips are used as MPSPM probes. By using the nanorod probes, unusual resistance change is detected in the electrical measurements, which would be related to electron mean free path.

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  The authors introduce recent progress in the measurements of molecular wires in relation to the research on molecular devices. The miniaturization limit of fabrications has been approaching to molecular sizes, and it is sufficient to produce nano-gap electrodes for measuring single-molecular conductance. However, connecting molecular wires to the electrodes requires a molecular design enabling stable chemical bonds between the molecule and two facing electrodes. In this manuscript, the authors demonstrate a simple procedure for fabricating molecular-sized nanogap electrodes and a statistical analysis about the success rate of forming connection between the nano-gap for three molecular wires with slightly modified structures. It was found that the steadiness of the bridge-structure depended strongly on the molecular structures. In addition, the authors combined the nano-gap electrodes with sensor molecules and successfully detected target molecules by the change of molecular conductance caused by the reaction to the target.

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  Quantum dots have been fabricated in an individual single-wall carbon nanotube (SWCNT), and single electron transport measurements have been carried out at low temperatures. It is demonstrated that the SWCNT quantum-dot can be considered as an artificial atom where electrons are confined in a one-dimensional hard-wall potential. A shell structure and shell filling in magnetic fields are shown, and the excitation energy spectrum in magnetic fields was obtained for one or two electrons in a shell. A striking observation may be that quantum states of an interacting two-electron system were observed as singlet and triplet states which have energy difference at zero magnetic field. Reflecting energy scales associated with the SWCNT artificial atom, a quantum response to THz wave was, for the first time, observed in quantum dots as a photon assisted tunneling.

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  Several examples are known in which massive arrays of metal atomic chains are formed on semiconductor surfaces that show quasi-one-dimensional electronic structures. Here, Au chains on Si(557) and Si(553), and In chains on Si(111) surfaces are introduced and discussed with experimental data of scanning tunneling microscopy, angle-resolved photoemission spectroscopy, and electrical conductance measurements. They show quasi-one-dimensional Fermi surfaces and parabolic band dispersion along the wires. All of them exhibit metal-insulator transitions and charge-density wave formation due to Peierls instability of the metallic chains. The electrical conductivity, however, reveals the metal-insulator transition only on the less-defective surfaces, while a defective surface does not. The importance of atomic-scale defects on quasi-one-dimensional systems is demonstrated by showing the dramatic decrease of conductivity along the metallic wires with increase of the defect density.

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  Using a transmission electron microscope combined with a scanning tunneling microscope, we find that the gold nanowire with the axis along the [110] direction shows quantized conductance clearly. The conductance histogram taken from three hundreds of thinning processes for the gold <110> nanowire shows nearly regular conductance peaks with a step of quantized unit of conductance below 30G₀(=2e²/h). We determine conductance value of each stable gold <110> nanowire with symmetric hexagonal cross-section from analyzing the TEM images viewed from two different directions. For example, the nanowire consisting of seven or twelve <110> atomic rows has conductance of 6 or 9 G₀, respectively.

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  The electrical properties of metallic contacts with nanometer width (nanocontacts) are reviewed. First, the production methods of nanocontacts and structural dynamics during formation are introduced. Then, the characteristics of conductance in nanocontacts with various metallic elements are presented. The origins of stepwise variation in conductance-time curves and peaks in conductance histograms are described in contrast with that observed in electron-gas point contacts at semiconductor interfaces. In particular, the conductance of gold nanocontacts is explained in relation to quantization of conductance. The atomic configuration and conductance of single-atom wires are also reviewed.

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  Present status and challenges in vacuum tribology are briefly reviewed. For vacuum applications, lubricats which have low vapor pressure and good tribological performance are required. Solid lubricants have beeen widely adopted for vacuum applications due to their low vapor pressure. One big drawback of solid lubrication is limited life. To achieve long life, a method to supply lubricant during operation is desired. Synthetic liquid lubricants having low vapor pressure have been also used in vacuum due to its better tribological performance than solid lubricant. However, operational temperature of liquid lubricants is limited: liquid lubricants freeze at low temperature, and outgassing and/or vaporization become noticeable at high temperatures. Outgassing from the lubricants causes not only lubricant loss but also contamination of vacuum sysytem. The future challenges in vacuum tribology include lubricant supply system during operation, solid lubricant which can be used both in vacuum and humid air, new liquid lubricant with lower vapor pressure, and low vapor pressure additives for liquid lubricant.

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  The tribological properties of ionic liquids are outlined in terms of their chemical structure. Advantages of imidazolium cation and bis (tetrafluoromethylsulfonyl) imide are pointed out. Improvement in the tribological properties is possible by applying additives such as simple carboxylic acids. Requirements in ionic liquids as advanced lubricants are outlined.

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  Thin film lubricants and high-temperature solid lubricants are discussed as the latest alternatives to fluorine grease. These lubricants feature lower outgassing for clean and vacuum environments. Specifically, they produce less organic contamination associated with particle emissions and outgassing, and are capable of being operated under conditions up to 200°C. For conditions exceeding 200°C, improvements made to bearing design allow for the use of high-temperature solid lubricants.

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  The technical trend of solid lubricant rolling bearing and linear motion guide was reviewed. Especially, a newly developed oil-free solid lubricant linear motion guide by authors was also reported in details in this present. The rolling ball of the guide was coated by sputtering molybdenum disulfide (MoS₂) and some special transition metal simultaneously, while the spacer ball made of polytetrafluoroethylene (PTFE) was also applied to the guide. By this way, a composite solid lubricant with excellent wear resistance properties was provided and there has been no any organic solvent and binder added, resulting in lower particle generation and low lever of out gas. It is expected that the oil-free solid lubricant linear motion guide could be applied to high temperature, high vacuum, radiation and space utilizations.

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  Lubrication is one of the most important key technologies for reliable and durable machines in ultra high vacuum. Solid lubricants, which are pre-coated before operation by a certain amount thickness, are commonly used for the system. The life of present system is, therefore, determined by the wear life of the coating of lubricant.
  To extend its lifetime, a new lubrication method for in-situ and on-demand restoration of the lubricants called as “Tribo-coating” had been introduced, and its effectiveness as practical solid lubrication method for sliding element has been clearly shown.
  This paper introduces the unique advantage of excellent tribological performance of tribo-coating film for ball bearings, and the usefulness of the tribo-coating for friction control of ball bearings in ultra high vacuum is clearly shown.

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  The isotherms and the isobars of krypton and xenon physisorbed on a silver single crystal surface were investigated by ellipsometric observation of the amount of adsorption. It was found that they showed a hysteresis in an adsorption-desorption loop for both the first and the second layer condensations. Careful examination of the effect of instability of an equilibrium pressure and a substrate temperature during the measurement revealed that they were not responsible for hysteresis. The observed hysteresis is very likely to be intrinsic one though its origin and mechanism are unknown.

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  We developed mass product type c-BN thin films coating equipment for cutting tool. Our coating method is magnetically enhanced plasma ion plating (MEP-IP).
  Distinction of our coating system have 100 kHz of substrate power supply frequency and stabilized plasma source for insulated c-BN coating. With these distinctions, c-BN thin film didn't peel from substrate and composition of c-BN thin film became stable.
  The c-BN film by using this equipment has practical deposition rate 1.0 μm/h, high hardness 4000 HK, low friction coefficient 0.17, and high performance of cutting property.

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