The Thermal Conductivity of the Second Kind Superconductors In-Pb Alloys

The thermal conductivity of three specimens of indium lead alloys, which belong to the second kind superconductors, has been measured as a function of temperature in magnetic fields, in which the specimens go through the mixed state at intermediate temperatures. In the mixed state there appears a minimum value of the thermal conductivity in the temperature variation as well as in the field variation. The measured thermal conductivity is in good agreement with that calculated from the magnetization by using an average energy gap model proposed by Dubeck et al