Non-Equilibrium Electron Gas in Solids

Abstract

An ideal Fermi gas, in particular an electron gas in an equilibrium state, is dealt with in Chap. 7. There the state equation is found, thermodynamic coefficients are calculated and Pauli’s paramagnetism due to the free electron spin in metals is investigated.

In this chapter electron gas in metals and semiconductors is dealt with in a nonequilibrium state. Nonequilibrium processes associated with charge carriers' motion in a crystal under external disturbances such as electric field, temperature gradient, magnetic field, etc. are referred to as electron transport phenomena or kinetic effects. They include electric conductivity, thermal conductivity, thermoelectric, galvanomagnetic and thermomagnetic effects.

If the values governing transport phenomena, i.e. electric current density, heat flux, electric field strength, etc. do not depend on time, the charge or energy transport process is referred to as stationary. Here, we shall discuss stationary transport phenomena only. The definition and classification of these phenomena are presented below.

In the classical case, the Boltzmann equation for a nonequilibrium charge carrier distribution function which accounts for the interaction with a crystal lattice is used to construct a microscopic theory of transport phenomena.