Gapless superconductivity and variation of {T_c} in the heavy-fermion system {CeCu_2Si_2}

C D Bredl, H Spille, U Rauchschwalbe, W Lieke, F Steglich, G Cordier, W Assmus, M Herrmann, J Aarts

Publikation: Beitrag in FachzeitschriftKonferenzaufsatz in FachzeitschriftForschungBegutachtung


Polycrystalline samples of CeCu2Si2 exhibit bulk superconductivity carried by "heavy fermions". While usually Tc [almost equal or equal to] (0.55 +/- 0.15) K, a few samples showed considerably lower transition temperatures (Tc [greater-or-equal, slanted] 0.11 K), which could, however, be raised to usual values by proper heat treatment. We found that lower Tc's are accompanied by both slightly reduced values of the spin-fluctuation temperature of the Ce3+ ions and the phenomenon of "gapless superconductivity". In agreement with recent results by Aliev et al. [5], a CeCu2Si2 single crystal did not become superconducting above 20 mK, but showed a 20% deficiency in Cu occupation.
ZeitschriftJournal of Magnetism and Magnetic Materials
AusgabenummerPart 1
Seiten (von - bis)373-376
PublikationsstatusVeröffentlicht - 1983