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早川 虹雪*; 村口 正和*; 馬酔木 ゆめの*; 小島 洋一郎*; 小田 将人*; 藪田 莉名*; 石井 宏幸*; 本田 充紀
e-Journal of Surface Science and Nanotechnology (Internet), 23(3), p.290 - 295, 2025/07
環境調和型の高温で動作する熱電材料へむけて、粘土鉱物を利用した材料開発を進めている。高温で熱電特性をえることに成功したが、なぜその特性を示すかは分からない。そこで高温環境下で風化黒雲母の構造変化を解明するためのXAFS分析手法の開発し、高温でのFeの局所構造を明らかにする。大気環境と真空環境で焼結した試料のFeの局所構造解析からFeの化学結合状態の変化を明らかにした。
深谷 有喜
no journal, ,
Stanene, the tin counterpart of graphene, is theoretically predicted to have a finite bandgap due to the strong spin-orbit interaction, suggesting the realization of two-dimensional topological insulator at room temperature. Owing to small lattice mismatch, InSb(111) surfaces are often utilized as a template for crystalline Sn thin film growth. When the coverage of deposited Sn atoms corresponds to one monolayer, the buckled honeycomb structure of stanene is possibly formed on the InSb(111) surface. Actually, the electronic band structure calculated using stanene is in good agreement with angle-resolved photoemission spectroscopy experiments, except for a slight difference in band gap width. However, the structure of Sn layer on the InSb(111) surface remains uncertain because the structure analysis has not yet been done. In this study, we investigated the structure of Sn layer on the Sb-terminated InSb(111) surface using total-reflection high-energy positron diffraction (TRHEPD). The structure analysis based on dynamical diffraction theory revealed that Sn layer with half the atomic density of stanene is formed on the surface, which is significantly different from previous studies.
和田 薫*; 志賀 隆史; 岡橋 和成*; 神谷 潤一郎; 小畠 雅明; 諸橋 裕子; 阿部 一英; 岸川 信介*; 佐々木 優直*; 黒岩 雅英*; et al.
no journal, ,
東京電子は、BeCu(ベリリウム銅)材料を用いた超高真空装置を製造・販売しており、日本原子力研究開発機構の持つNEG(非蒸発型ゲッター)コーティング技術を活用し、この二つの技術を組み合わせることで、無電源で動作するゲッター型BeCu真空チャンバーを開発した。実験では、大気開放後に真空排気を行い、200
Cで8.5時間のベーキング(活性化)処理を5回繰り返して圧力を測定した。NEGコーティングした方が、排気速度が向上し、到達圧力が低下することを確認した。さらに、ビルドアップの測定においても、同様のプロセスを経て5回の測定を行った結果、試験前の圧力には大きな差がないものの、回数を重ねるごとにNEGコーティングの有無で圧力に顕著な差が生じた。これにより、NEGコーティングが真空システムの効率を高め、超高真空環境の維持において重要な役割を果たすことが実証された。
津田 泰孝; 吉越 章隆; 小川 修一*; 高桑 雄二*
no journal, ,
Oxidation-induced point defect generation plays a dominant role to progress Si dry oxidation processes as experimentally observed. Vacancy-derived states are concerned with the excess minority carrier recombination at SiO
/Si interface, giving rise to activating the vacancy site for O dissociative adsorption occurring through trapping-mediated adsorption. The SiO growth at the vacancy site brings additional point defect generation, making it possible to drive two kinds of oxidation reaction loops: Single-step oxidation reaction (Loop A) and double-step oxidation reaction (Loop B). This concept is referred the Loops A/B model. A good linear correlation between the amount of O(chem) and oxide growth rate for the interfacial oxidation region is clear evidence for the Loops A/B model. In this study, XPS at SPring-8 is employed to confirm the Loops A/B model for the surface oxidation region on p-Si(001) and n-Si(001) surfaces, where dimer dangling bonds participate additionally in the Loops A/B model as O dissociative adsorption sites.
本田 充紀; 早川 虹雪*; 村口 正和*; 馬酔木 ゆめの*; 小田 将人*; 飯野 千秋*; 石井 宏幸*
no journal, ,
本研究は、セラミック湿度センサー材料の新たな創製方法として、風化黒雲母(WB)から溶融塩法を利用して選択的な和田石合成法を開発した内容である。湿度センサー材料の母体となる和田石は、WBにCsを層間に吸着させることにより効率的に選択的に合成されることを明らかにした。
神谷 潤一郎; 諸橋 裕子; 武石 健一; 和田 薫*
no journal, ,
The benefits of the metal Additive Manufacturing (AM), known also as 3D printing are consolidation of multiple different part components into one manufacturing process, manufacturing custom-made products without expensive mold tool, possible complex design which is not produced by ordinary machining, etc. It is important to investigate how this beneficial technology, metal AM, can be effectively used in the vacuum field. This study examined the feasibility of using metal AM for the vacuum chamber fabrication was examined. We focused on the following points. (1) Does AM vacuum chamber achieve vacuum without leak or permeation? (2) Doesn't AM vacuum chamber have large outgassing due to the large surface roughness? (3) What is the outgassing component of the AM vacuum chamber? (4) Is there any way to use the characteristics of AM to the advantage of the vacuum? For the first point, although hot isostatic pressing (HIP) would be the solution to remove the possible void or leak path between the melted powder, it was not adopted to the current chamber. For the second point, although the surface roughness can be reduced by the post surface treatment such as mechanical polishing and chemical or electrical polishing, they were not adopted to the current chamber. We will show the vacuum performance results of the AM vacuum chamber in the conference. Furthermore, for the fourth point, NEG coating to the inner surface of the AM chamber has the advantage because the effective large surface area due to AM rough surface, can be used for the getter surface not as outgassing source. We also show the measurement result of this novel used of AM vacuum chamber.
鈴木 誠也; 小澤 孝拓*; 植田 寛和; 福谷 克之
no journal, ,
Germanene, a graphene-like atomic sheet of Ge, has attracted immense attention owing to its theoretically predicted outstanding 2D topological properties. However, because of its chemical instability, electronic devices of germanene have not yet been reported. As one approach, hydrogenation is expected to increase the chemical stability of germanene, leading to the realization of germanene electronic devices. Here, we report on the direct hydrogenation of germanene by atomic hydrogen exposure. The germanene sample was prepared by the segregation method on a Ag(111)/Ge(111) substrate. The atomic hydrogen was generated by cracking of H
molecules with a hot tungsten filament. We have studied the hydrogenation of germanene by fourier transform infrared (FT-IR) spectroscopy, themal desorption spectroscopy, and low energy electron diffraction.
