Study on the mechanism of novel method to control oxidation by block the diffusion path at the lattice defects level

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K22035
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 26:Materials engineering and related fields
• Research Institution: Hokkaido University
• Principal Investigator: SHIBAYAMA TAMAKI 北海道大学, 工学研究院, 教授 (10241564)
• Co-Investigator(Kenkyū-buntansha): 中川 祐貴 北海道大学, 工学研究院, 助教 (00787153)
• Project Period (FY): 2019-06-28 – 2022-03-31
• Keywords: Heイオン / 銅 / 照射効果 / 酸化 / 拡散

Outline of Final Research Achievements

He ion irradiated pure copper shows less oxide crystal or film formation on the surface. To study their oxidation resistance properties, He ion irradiated pure copper was oxidized in air at low temperatures or in NaOH aqueous solution at room temperature. After oxidation, the microstructure evolution on the surface and inside were evaluated in atomic scale by Cs-STEM/EELS, etc. As a result of microstructure investigations, it was clarified that the He interstitial atoms and irradiation defects would play a role of a diffusion barrier to oxygen, and the carbon-based film formed on the surface during He ion irradiation also suppressed the oxidation on the surface.

Free Research Field

量子ビーム工学

Academic Significance and Societal Importance of the Research Achievements

電気伝導に優れるが酸化しやすい純銅にHeイオンを照射し、格子間位置や粒界にHe原子が存在することによって酸素の拡散経路を塞ぎ酸化を抑制出来るか検討した。その結果、He格子間原子や照射欠陥が酸素の拡散バリア層となると共にHeイオン照射中に、表面に形成した炭素を主体とする皮膜により表面の酸化を抑制することが初めて明らかになった。薬剤を使用しないため電子部品の長寿命化や環境低負荷に貢献できると考えられる。