1997/12/15 by S. V. Shulga, S. -L. Drechsler, S.‐L. Drechsler +8 · 8 citations
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Rare-earth and actinide compounds #Superconductivity in MgB2 and Alloys #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.80.1730
4 pages, 2 figures, Phys. Rev. Lett. accepted
arxiv created 1997/12/15 · openalex publication_date 1998/02/23 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We present new upper critical field Hc2(T) data in a broad temperature region 0.3K\ensuremath≤T\ensuremath≤Tc for LuNi2B2C and YNi2B2C single crystals with well characterized low impurity scattering rates. The absolute values for all T, in particular, Hc2(0), and the sizable positive curvature (PC) of Hc2(T) at high and intermediate T are explained quantitatively within an effective two-band model. The failure of the isotropic single-band approach is discussed in detail. Supported by de Haas--van Alphen data, the superconductivity reveals direct insight into details of the electronic structure. The observed maximal PC near Tc gives strong evidence for clean limit type-II superconductors.