Critical temperature in bulk ultrafine-grained superconductors of Nb, V, and Ta processed by high-pressure torsion

Terukazu Nishizaki, Kaveh Edalati, Seungwon Lee, Zenji Horita, Tadahiro Akune, Tsutomu Nojima, Satoshi Iguchi, Takahiko Sasaki

    研究成果: Contribution to journalReview article査読

    3 被引用数 (Scopus)

    抄録

    This overview describes the progressive results of the superconducting critical temperature in bulk nanostructured metals (niobium, vanadium and tantalum) processed by high-pressure torsion (HPT). Bulk nanostructured superconductors provide a new route to control superconducting property, because ultrafine-grain structures with a high density of grain boundaries, dislocations, and other crystalline defects modify the superconducting order parameter. The critical temperature Tc in Nb increases with the evolution of grain refinement owing to the quantum confinement of electrons in ultrafine grains. In V and Ta, however, Tc decreases at a certain HPT revolution number (i.e. at certain strain levels). The different behaviour of Tc in the three materials is explained by the competition effect between the quantum size effect and disorder effect; these effects are characterized by the parameters of grain size, electron mean free path, and superconducting coherence length.

    本文言語英語
    ページ(範囲)1367-1376
    ページ数10
    ジャーナルMaterials Transactions
    60
    7
    DOI
    出版ステータス出版済み - 1 1 2019

    All Science Journal Classification (ASJC) codes

    • 材料科学(全般)
    • 凝縮系物理学
    • 材料力学
    • 機械工学

    フィンガープリント

    「Critical temperature in bulk ultrafine-grained superconductors of Nb, V, and Ta processed by high-pressure torsion」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

    引用スタイル