抄録
The relation between thermal conductivities of superconductors (Nb3Sn, V3Ga) and temperature was studied. We used the steady-state comparative-plate method which is suitable for measuring the thermal conductivities of superconductors at low temperatures. For our experiment, a reference metal of lead was placed in series with a superconductor specimen. This method has the advantages of a simpler setup for both the specimen and the equipment. The temperature was measured with AuFeCr thermocouples embedded in copper grooves on the superconductor specimen. The thermal conductivities of the superconductors gave obviously lower values in the region below the transition temperatures as compared with the thermal conductivities of normal conductors. The nondimensional thermal conductivities, λ/λc, normalized by the thermal conductivities at the transition temperatures of Nb3Sn and V3Ga for a nondimensional temperature, T/Tc, were found to be given by a generalized curve (identical to a theoretical curve obtained using a theory developed in the present study based on the B. R. T. theory).
