Hebel-Slichter peak and superconducting energy gap in Rb<sub>3</sub>C<sub>60</sub> observed by muon spin relaxation

Citation:
Macfarlane, WA, Kiefl RF, Chow KH, Dunsiger S, Duty TL, Johnston TMS, Schneider JW, Sonier J, Brard L, Strongin RM, Fischer JE, Smith AB.  1994.  Hebel-Slichter peak and superconducting energy gap in Rb3C60 observed by muon spin relaxation. Hyperfine Interactions. 86:467-472.

Keywords:

dynamics, state

Abstract:

Muon spin relaxation has been observed in both the normal and superconducting states of Rb3C60 (T(c) = 29.3K). The field dependence of the T1 spin relaxation rate is due to muonium undergoing spin-exchange scattering with conduction electrons, making this the first observation of muonium in a metal. The temperature dependence of T1(-1) shows a Hebel-Slichter coherence peak just below T(c) which is not seen in C-13 spin relaxation. The peak can be fit assuming spin relaxation due to interaction with the quasiparticle excitations of a BCS superconductor provided the density of states is broadened relative to that of BCS. Such fits yield a value for the zero temperature energy gap, DELTA0/k(B), of 53(4)K, consistent with weak-coupling BCS.

Notes:

n/a

Website

DOI:

10.1007/bf02068935