1.8 Transport properties

The flow of either either electricity or heat is regarded as transport. These properties are of tensorial nature and are reviewed in this chapter. The topic is restricted to steady-state flows and to linear response. The three main transport coefficients are the electrical conductivity, the thermal conductivity and the Seebeck coefficient. Section 1.8.3 concerns the electrical resistivity of metals and semiconductors and the Hall effect. Section 1.8.4 concerns the thermal conductivity. Heat flow can be carried by two kinds of excitations: phonons and electrons. The cases of boundary scattering, impurity and defect scattering, isotope scattering and alloy scattering are distinguished as well as anharmonic interactions. The last section, Section 1.8.5, describes the properties of the Seebeck coefficient.