Magneto-thermal-switching in type-I and type-II superconductors

Thermal switching by applying magnetic field is one of the key technologies in thermal management in electronic devices. In low-temperature devices, superconductors can be used as a magneto-thermal-switching (MTS) materials due to the large change in carrier thermal conductivity by the superconducting transition. In this study, we measured the temperature ( T ) and magnetic field ( H ) dependences of thermal conductivity ( kappa ) of Sn, Ta and V to enrich knowledge on MTS of type-I and type-II superconductors. From the data analyses, we found different trends of kappa - H curves in type-I and type-II superconductors. The normalized kappa - H curves of type-I superconductors showed the similar behavior, which is solely governed by H c . However, the kappa - H curves of type-II superconductors were affected by the H c1 and H c2 , and its behavior greatly depends on the materials. In addition, we investigated the elemental composition of Sn and Ta to explore the origin of weak hysteresis in the kappa - H curves and revealed the importance of impurity on the hysteresis of kappa - H curves.