Point-contact study of the heavy-fermion superconductor CeCoIn5

We have investigated the differential conductance spectra of the point contacts between the heavy-fermion superconductor CeCoIn5 and Pt. Many of them show a double-maximum structure that indicates the superconducting energy gap (sic). The (sic) values derived using Blonder-Tinkham-Klapwijk model, however, varies from 0.47 to 0.77 meV, and yet they are within the scatter of the reported values. The evolution of (sic) below T-c is slow as compared with that of BCS gap probably reflecting the unconventional superconductivity in CeCoIn5. (c) 2008 Elsevier Ltd. All rights reserved.