2008/01/20 by Sangita Bose, Charudatta Galande, S P Chockalingam +4
Physics and Astronomy · #Physics of Superconductivity and Magnetism #Superconductivity in MgB2 and Alloys #Surface and Thin Film Phenomena #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1088/0953-8984/21/20/205702
published as J. Phys.: Condens. Matter 21, 205702 (2009) · pdf file with figures
arxiv created 2008/01/20 · openalex publication_date 2009/04/24 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
The superconducting transition temperature (T(C)) in nanostructured Pb decreases from 7.24 to 6.4 K as the particle size is reduced from 65 to 7 nm, below which superconductivity is lost rather abruptly. In contrast, there is a large enhancement in the upper critical field (H(C2)) in the same size regime. We explore the origin of the unusual robustness of T(C) over such a large particle size range in nanostructured Pb by measuring the temperature dependence of the superconducting energy gap in planar tunnel junctions of Al/Al(2)O(3)/nano-Pb. We show that below 22 nm, the electron-phonon coupling strength increases monotonically with decreasing particle size, and almost exactly compensates for the quantum size effect, which is expected to suppress T(C).