The structural change of C₆₀ nanotubes (C₆₀NTs) by heating in vacuum was investigated using thermo-gravimetric analysis (TGA), transmission electron microscopy (TEM) and Raman spectroscopy. The C₆₀NTs were prepared by use of a pyridine solution saturated with C₆₀ and isopropyl alcohol (IPA). A weight loss of about 4 % in the C₆₀NTs dried at room temperature was observed by heating up to 400°C in a N₂ atmosphere, and the C₆₀NTs started to decompose from about 600°C. The A_g(2) peak of as-prepared C₆₀NTs shows a Raman shift indicating one-dimensionally polymerized C₆₀, while the C₆₀NTs heated at 100°C ∼ 500°C in vacuum show Ag(2) peaks characteristic of van der Waals C₆₀ crystals, suggesting a change of bonding state of C₆₀ molecules by heat treatment. TEM observations show that the crystallinity and surface morphology of C₆₀NTs are degraded by high-temperature heat treatment in vacuum.

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The mechanical properties of C₆₀ nanowhiskers (C₆₀NWs) grown in a solution by a liquid-liquid interfatical precipitation method were investigated by a bending method. C₆₀NWs in the solution exhibited large elastic deformation where they recovered for large bending with a curvature of 290 μm. On the other hand, C₆₀NWs in air were broken even for small bending with only a 650 μm curvature. From the analysis of the bending, the yield stress or breaking stress for C₆₀NWs in air is estimated to be 7.7 MPa, that is larger by one order compared with 0.7 MPa for bulk C₆₀ crystals. In addition, it is shown that the Young's modulus for C₆₀NWs in the solution is 8.9 GPa, that is below a half of 20 GPa for bulk C₆₀ crystals.

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Various Si molds with different side wall roughness were fabricated and the demolding forces for the thermal imprint to PMMA film were examined. The pattern size was the 2 μm half pitch line and space with the aspect ratio of about 2. The demolding force greatly depended on the side wall roughness of the mold. The demolding force normalized by the total side wall area of line patterns was 0.34 MPa for the smooth side wall mold.

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This paper reports a capacitive vacuum sensor with a bi-layer diaphragm made of silicon carbide (SiC) and polysilicon for uses in corrosive environments like etchers. The diaphragm side is completely covered with SiC to avoid corrosion, and electrical contacts are placed on the opposite side for easy packaging. This vacuum sensor design was realized with a sealing of the pressure reference room achieved by Au-Si eutectic bonding. In spite of incomplete sealing of the pressure reference room, the fabricated vacuum sensor was evaluated using a laser Doppler meter and an impedance analyzer.

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