The low-temperature specific heat C(T,H) of the superconductor MgCNi 3 has been measured in detail. ΔC/γ n T c = 1.97 is estimated from the anomaly at T c . At low temperatures, the electronic contribution in the superconducting state follows C es /γ n T c ≈ 7.96 exp(-1.46T c /T). The magnetic-field dependence of γ(H) is found to be linear with respect to H. T c estimated from the McMillan formula agrees well with the observed value. All the specific-heat data appear to be consistent with each other within the moderate-coupling BCS context. It is amazing that such a superconductor unstable to ferromagnetism behaves so conventionally. The Debye temperature Θ D = 287 K and the normal state γ n = 33.6 mJ/mol K 2 are determined for the present sample.
|Number of pages||4|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - 1 Feb 2003|