For realizing single molecular devices using metal-molecule-metal junction, it is necessary to fabricate a steady conductive bridge-structure. Recently, our group reported a molecular bridging method using migration of gold atoms on static nanogap electrodes. It was proposed that repeated cycles of single-molecular-bridging and breaking between benzene-di-thiolate (BDT) molecules and nanogap electrodes using this method. In this paper, to confirm the bridging condition during the cycles, current-voltage curves in each state were investigated. This result indicates that characteristic orbital energies of BDT were revealed while observed conductance was close with 11.0 mG₀. On the other hand, when the observed conductance was below 11.0 mG₀, the magnitude of estimated orbital energies was the similar as that using nanogap electrodes which were not covered by any molecules, which explained that direct tunneling conduction between Au electrodes was dominant. This clearly indicates that cycles between molecular-bridging and disconnection were realized using static nanogap structures.

The outgassing rates of aluminum alloys (A5052) with four types surface finishes, i.e. conventional mechanical grinding (MG), mechanical grinding with optimized process (OMG), combination of mechanical grinding and chemical polishing (MG＋CP) and combination of optimized mechanical grinding and chemical polishing (OMG＋CP), were investigated using the measurement systems with ultimate pressure of 10^－10 Pa. For without baking, the outgassing rates of all surface finished aluminum alloys were changed in time from 10^－7 to 10^－8 Pa m³ s^－1 m^－2 from 5 to 70 h after the start of vacuum pumping and MG ≫ OMG ≈ MG＋CP ≥ OMG＋CP was obtained for these rates. For after baking, the outgassing rates of all samples showed 10^－12 Pa m³ s^－1 m^－2 and MG ≫ MG＋CP ≈ OMG ≈ OMG＋CP was obtained for these rates. The outgassing rates of the OMG and the OMG＋CP were almost same with lowest outgassing rate in previous studies.

β-FeSi₂ is expected to produce an efficient bandpass filter for its bulk is transparent and has a high refractive index (for wavelength＞1.55 µm). However, it was found that β-FeSi₂ thin film has a different extinction coefficient from the bulk and a significant absorptance in the infrared region. We carried out experiments to research the relationship between the absorptance and composition of β-FeSi₂ thin film using co-sputtering by control the applied power on FeSi₂ and Si targets. The β-FeSi₂ thin film deposited at an applied power of 10～12 W on Si target had a correct stoichiometry and the minimum absorptance of approximately 0. It is suggested that high refractive index and low extinction coefficient in the infrared spectrum of β-FeSi₂ thin film can be successfully produced in this method and used for bandpass filters to enhance the efficiency in the Thermophotovoltaic power generation system.

Helium ion microscopy (HIM) is similar to scanning electron microscopy (SEM), which uses a helium ion beam instead of an electron beam. The contrast of HIM secondary electron images, HIM backscattered ion images, and SEM images are not identical because the incident and signal particles are different.

In this paper, the images measured in 2020 were compared with those measured in 2012 under the same conditions, and the reason of the differences of some elements due to aging were discussed. Surface oxidation affected the change for the eight years. However, the change was not as simple as the highly oxidizable elements changing significantly. This indicates that whether changes are observed or not depends on the combination of the thickness of the oxide layer and the mean free path of the signal particles.

A unique molecularly chemisorption of H₂ occurs on some stepped surfaces in addition to the typical adsorption schemes of physisorption and dissociation. In the present study, the rotational state and ortho-to-para (o-p) conversion of the molecularly chemisorbed H₂ on Pd(210) at a surface temperature of 50 K were probed by combining a pulsed molecular beam, photo-stimulated desorption and resonance-enhanced multiphoton ionization techniques. We experimentally demonstrated that the o-p conversion proceeds with a conversion time constant of ～2 s that is 2–3 orders of magnitude smaller than those reported for physisorption systems. The origins of such fast conversion and the rotational state distribution of H₂ in molecular chemisorption state are discussed.