Determination of the energy gap of superconducting Chevrel and A15 compounds from heat capacity measurements

Abstract

The heat capacities of numerous Chevrel compounds and of the A15 compounds Nb3Sn, Nb3Al, and V3Ge were measured at low temperatures and decomposed into electronic, and lattice parts. The zero-temperature thermodynamic critical fieldHc(0) and energy gap Δ were determined from the electronic part. Theoretical energy gap values were calculated, employing the theory of strong coupling superconductors. A satisfactory agreement between theoretical and experimental values is obtained.