Chapter 10 - Thermal properties

Abstract

This chapter discusses different thermal type properties of superconductors. The chapter also contains more extensive sections on various thermomagnetic and thermoelectric effects and the thermal conductivity. Thermoelectric and thermomagnetic phenomena are sensitive probes of the nature of electronic states and interaction processes within a conductor. As such they are useful tools to study the carrier dynamics and band structure of conducting solids. In superconductors, apart from providing valuable insight into the carrier transport above the superconducting transition temperature, the thermoelectric and thermomagnetic effects are important in assessing the dynamics of quasiparticles and vortices. Among the important properties of high-temperature superconductors (HTS) is their ability to conduct heat. There is not only an obvious technological interest in how efficiently and by what means the heat flows in these solids, but also a deep theoretical desire to understand the vibrational and electronic properties of these materials. Measurements of the thermal conductivity can be accomplished by various experimental arrangements depending on the structural form of a sample, temperature interval of interest, and the desired accuracy of the data. The lowering of the temperature below the superconducting transition temperature and the ensuing formation of the Cooper condensate leads to a sharp change in the electromagnetic and kinetic response of a material, and a consequent drastic modification of its heat flow pattern.