We have measured the magnetization M(T, H) and the resistivity p(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 Tc and the critical current density Jc increase. The enhancement of Tc is consistent with the size effect for nanoscale superconductors. The increase of Jc can be explained by the enhanced vortex pinning due to the introduction of lattice defects such as dislocations and grain boundaries.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering