Conventional s-wave pairing in the presence of spin fluctuations in superconducting Mo3Sb7 from specific heat measurements

The superconducting properties of the spin fluctuation- superconductor Mo3Sb7 have been investigated by specific heat measurements down to 0.5 K and under magnetic fields of up to 2 T. The obtained temperature and magnetic field dependences of the electronic specific heat strongly suggest a conventional s- wave pairing, while possible ( s+ g )- wave pairing symmetry has been proposed earlier. In addition, the temperature dependence of the upper critical field H-c2 is fully consistent with the Werthamer - Helfand - Hohenberg theory predicting its behavior for a conventional phonon- mediated type II superconductor.