Creation of unique Nb3Sn superconducting layer diffusion reaction behavior by intermediate active layer

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K04249
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21050:Electric and electronic materials-related
• Research Institution: National Institute for Materials Science
• Principal Investigator: BANNO Nobuya 国立研究開発法人物質・材料研究機構, 機能性材料研究拠点, 主幹研究員 (30354301)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 超伝導材料 / 冶金学 / ニオブスズ / 拡散反応 / 結晶組織 / 磁束ピンニング / 元素添加

Outline of Final Research Achievements

In order to achieve a breakthrough in the performance of Nb3Sn superconductors, we aimed to discover a "unique" Nb3Sn diffusion reaction phenomenon using an intermediate Cu-X active layer, which will lead to the creation of new functions. Zn, Ge, and Mg were examined as the X element. It was clarified that the effect of suppressing grain coarsening was observed in all of Zn, Ge, and Mg additions, and that the effect of grain refinement was further enhanced by the simultaneous addition of Zn and Mg. It was also found that the addition of Zn specifically formed a β-CuZn layer at the diffusion reaction interface, which contributes to significantly suppress voids. Studies on the location of Ti addition revealed that when Ti was added to the matrix, the Ti-Sn compound was refined and the diffusion of Sn in the Cu matrix was promoted.

Free Research Field

電気伝導性材料、超伝導応用

Academic Significance and Societal Importance of the Research Achievements

Nb3Sn超伝導体の組織制御に、新たな”自由度”を与える研究である。性能向上により、NMRや核融合炉、粒子加速器の高度化に貢献する。特に性能向上による強磁場NMR装置のコンパクト化は、市場への貢献が大きい。またNb3Snは臨界温度が18Kとヘリウム温度より10K以上高いので、今後需要の拡大が見込まれる医療用HeフリーMRIなどへの普及も期待される。