Behavior of high energy negative ion in a RF magnetron plasma with insulating oxide target is discussed. High energy O⁻ ions are produced on the target surface and are accelerated by oscillating RF sheath in front of the target. Maximum O⁻ energy that is influenced by the sheath thickness determined by the plasma density varies depending on the target surface position. O⁻ energy distribution shows fine-structure with many peak and valley. Origin of the fine structure is explained by the deceleration of O⁻ by the time-varying sheath potential, i.e., plasma potential in front of the wall.

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  Our group has been developing new functional thin films ‘switchable mirror’ which can be switched between transparent and mirror sates. Using switchable mirror thin film for window glass coating, new smart window is possible to be realized. Among various deposition methods, magnetron sputtering is the most suitable method to prepare switchable mirror thin films. In this paper, preparation and characterization of switchable mirror thin films using sputtering deposition method are reviewed.

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  Magnetic tunnel junctions (MTJs) have already been used for electronics devices such as magnetic read-heads of hard-disk drives and magnetic random memories. As the performance of such devices advances year by year, the requirements for the MTJs are getting strict. In order to fulfill such strict requirements, stack structure and deposition process of the MTJs have also been improved. This article focuses on the magnetic read-heads and the magnetic random access memories, and describes the technical trend of MTJs and progress in sputtering deposition technology.

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  The development of a quick pumping scheme into medium vacuum or ultra high vacuum (UHV) reduces not only the cost and the duration of pumping down, but it also reduce CO₂ emission that is known as one of serious cause of global warming. In this study, we aim for quick pumping into UHV without baking but with both introduction of well dried nitrogen gas into a chamber and improvement in the operation of the vacuum system. Baking and purging of a nitrogen gas line made of stainless steel have been applied in order to exclude water vapor, resulting in a dew point of −92℃ (0.065 vol. ppm) in the gas line. For practical reason we carried out nitrogen gas showering onto an open flange of the chamber, which reduced the pumping duration to achieve a pressure of 1×10⁻⁶ Pa to 3 hours, while it took 9 hours without showering. It turned out that the quick pumping of a UHV system with no baking operation was successfully achieved and could reduce the electric power consumption.

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  We study the ligand effect on the LUMO/HOMO of ligated zinc porphyrin (ZnP) by utilizing DFT. The ligated ZnPs are zinc meso-tetraphenylporhyrin (ZnTPP), zinc tetrabenzoporphyrin (ZnTBP), zinc meso-tetraphenyltetrabenzoporphyrin (ZnTPTBP) and five-coordination ZnTPP with imidazole (ZnTPP(Im)). The ligands decrease LUMO-HOMO energy gap (ΔE_g) of ligated ZnPs with respect to non-ligated ZnP, which is in good agreement with experiments. LUMO of ZnTPP and ZnTBP is stabilized by LUMO+1 (b₁-type, C_2v-symmetry) of respected ligands, while their HOMO is destabilized by HOMO−4 (a₁, C_2v) and HOMO (a₂, C_2v) of respected ligands. ΔE_g of ZnTPP and ZnTBP can be adjusted by changing the ligand's electronegativity, such as halogen substitution at the ligands. Halogenated ZnTPP has ΔE_g smaller than ZnTPP, which confirms the experiments. Geometry change in ZnP, which allows the intermolecular perturbation in the frontiers molecular orbitals, shifts LUMO/HOMO energies as it is shown for ZnTPP(Im) and ZnTPTBP. The calculated ΔE_g of ZnTPP(Im) and ZnTPTBP are greater than that of ZnTPP and ZnTBP.

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  At the J-PARC Main Ring synchrotron (MR), as the beam power is so high beyond a hundred kilowatts, a large increase of the vacuum pressure is observed during the beam acceleration periods. The change of the vacuum pressure has been recorded at the fixed point of the MR synchrotron ring for three years. The pressure growth normalized by the beam current was in inverse proportion to the total charge or the integrated beam current. The analysis shows the vacuum system is compatible with a future power-upgrade of the MR.

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  The Tokai area is one of big foothold in Japan with a large number of manufacturing industries and many universities and national research institutes for advanced research and development in the science and engineering field. In this article, the activity of Tokai Branch of The Vacuum Society of Japan, which is newly established in at 2012, is briefly introduced.

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