Superconducting properties in bulk nanostructured niobium prepared by high-pressure torsion

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• 作者：Terukazu Nishizaki ; Seungwon Lee ; Zenji Horita ; Takahiko Sasaki ; Norio Kobayashi
• 关键词：Bulk nanostructured Nb ; Grain refinement ; Magnetization ; Resistivity ; Critical temperature ; Critical current density
• 刊名：Physica C
• 出版年：2013
• 出版时间：15 October, 2013
• 年：2013
• 卷：493
• 期：Complete
• 页码：132-135
• 全文大小：1202 K

文摘

We have measured the magnetization M(T, H) and the resistivity ¦Ñ(T) in bulk nanostructured Nb prepared by high-pressure torsion (HPT) and studied the effect of the grain refinement on the superconducting properties. With increasing revolution numbers N of HPT, the critical temperature T_c and the critical current density J_c increase. The enhancement of T_c is consistent with the size effect for nanoscale superconductors. The increase of J_c can be explained by the enhanced vortex pinning due to the introduction of lattice defects such as dislocations and grain boundaries.