2005/02/28 by D. L. Bashlakov, D L Bashlakov, Yu G Naidyuk +11
Physics and Astronomy · #Physics of Superconductivity and Magnetism #Rare-earth and actinide compounds #Superconductivity in MgB2 and Alloys #cond-mat.supr-con
paper · pdf · doi:10.1088/0953-2048/18/8/012
published as Supercond. Sci. Technol. 18 (2005) 1094-1099 · 6 two-column pages, 7 figs; V2: as published, Fig.4 is modified
openalex publication_date 2005/07/05 · arxiv created 2005/07/06 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
The differential resistances R d = d V /d I ( V ) of point contacts between a normal metal and a c axis oriented YNi 2 B 2 C film ( T c = 15.2 K) in the superconducting (SC) state have been investigated. R d ( V ) contains clear 'gap' features connected with processes of Andreev reflection at the boundary between a normal metal and a superconductor that allow the determination of the SC gap Δ and its temperature and magnetic field dependence. A distribution of Δ from Δ min ≈1.5 meV to Δ max ≈2.4 meV is revealed; however, the critical temperature T c in all cases corresponded to that of the film. The value 2Δ max / k B T c ≈3.66 is close to the Bardeen–Cooper–Schrieffer (BCS) value of 3.52, and the temperature dependence Δ( T ) is BCS-like, irrespective of the actual Δ value. It is supposed that the distribution of Δ can be attributed to a gap anisotropy or to a multiband nature of the SC state in YNi 2 B 2 C, rather than to the presence of nodes in the gap.