Formation and control of nanostructure bundles by helium plasma exposure

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K22322
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0202:Condensed matter physics, plasma science, nuclear engineering, earth resources engineering, energy engineering, and related fields
• Research Institution: University of Tsukuba
• Principal Investigator: Hwangbo Dogyun 筑波大学, 数理物質系, 助教 (00870908)
• Project Period (FY): 2020-09-11 – 2022-03-31
• Keywords: タングステン / プラズマー材料相互作用 / ヘリウムプラズマ / ナノ構造バンドル

Outline of Final Research Achievements

Helicon-mode helium plasma was successfully demonstrated in the RF (13.56 MHz) frequency plasma device APSEDAS. A voltage bias system to a sample was established, and the formation of nanostructures was confirmed. It was found that the shape of the surface nanostructure differs with the change in plasma parameters during the helicon transition. It was also clarified that when impurities are observed in the early stage of plasma generation, the formation of uniform nanostructures is suppressed on the surface and needle-shaped nanostructure bundles are fabricated. It is considered that the RF ion modulation and the sputtering due to impurity contents affected the formation of the needle-shaped bundle structures. Succesive research would focus on clarying the effects of RF modulation of the biasing and the impurity concentration control experiment.

Free Research Field

核融合学

Academic Significance and Societal Importance of the Research Achievements

本研究は純金属とプラズマのみで発生する金属構造変化に注目する研究である。近年、ヘリウムプラズマに加えて不純物ガスの存在や金属面へ入射するイオンのエネルギー変調等が既存と大別されるバンドル構造を形成することを確認されており、本研究ではそのバンドル構造が一部の実験装置の特殊的な実験条件に限定される現象でなく、普遍的に発生する現象であることを示した。化学反応を含まない、ドライプロセスでの金属ナノ構造化は表面構造の制御技術の発展により光触媒、電界放出材、熱電素材など様々な応用が予想されるため、今後ともナノ構造やバンドル構造の生成機構の理解や構造制御技術の確立が期待できる。