LOW TEMPERATURE HEAT CAPACITIES OF SUPERCONDUCTING MOLYBDENUM CARBIDES

Low-temperature heat capacities from 1.5 to 20°K have been measured for several molybdenum carbides with closely related crystal structures. These carbides are found to have very similar thermodynamic and superconducting properties. This similarity, as well as their unusually high Tc's, can be explained by their related crystal structures. An experimental evaluation of the applicability of the GLAG theory(1) to these carbides shows that the upper critical field, Hc2, is limited by the Ginzburg-Landau κl parameter, in which the coherence length is limited only by the electron mean free path. © 1968.