Development of high energy state-selected O2 beam and the method for a high sensitivity measurement

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H03874
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Thin film/Surface and interfacial physical properties
• Research Institution: National Institute for Materials Science
• Principal Investigator: Kurahashi Mitsunori 国立研究開発法人物質・材料研究機構, 先端材料解析研究拠点, 主席研究員 (10354359)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 酸素分子 / 配向効果 / 白金 / 分子線

Outline of Final Research Achievements

The single spin-rotational state-selected O2 beam enables us to conduct spin and alignment- controlled surface oxidation experiments. But, because of the limitation of its beam energy range and sensitivity, only reactive surfaces were investigated with this method. In this project, the beam energy range was expanded to 0.1-0.9 eV by increasing the number of movable hexapole elements used and implementing the nozzle temperature control. The apparatus has been used for clarifying (1)the origin of the unusual behavior in O2 chemisorption on Pt(111) surface, and (2)the steric effect in Pt steps by utilizing the Pt(553) and (533) surfaces. Another apparatus combining the aligned O2 beam with laboratory XPS machine that allows us to measure the accumulated oxygen during the prolonged O2 beam irradiation was developed for investigating the alignment effect in O2 adsorption on inert surfaces.

Free Research Field

薄膜表面・界面物性

Academic Significance and Societal Importance of the Research Achievements

貴金属表面へのO2吸着は燃料電池や排ガス処理等において応用上重要な過程であり、原子レベルでの反応機構理解に向けた研究が長年行われてきたが、表面に飛来するO2分子の配向の影響は不明であった。本計画で開発した高エネルギー状態選別O2ビームによって初めて示された白金平坦表面、ステップ表面でのO2配向効果観測はこれを示す最初の観測であり、反応機構の理解に大きく貢献するものである。