Electron–phonon relaxation mechanisms in thermo-emf and magnetothermo-emf of noncompensated polyvalent metals with a closed Fermi surface
Abstract
The theory of thermo-emf in noncompensated polyvalent metals with a closed Fermi surface described by a weak pseudopotential is constructed under the conditions of predominance of small-angle electron–phonon scattering. The electron drag by phonons and the Umklapp processes are considered in detail. A qualitative explanation is offered for the experimentally observed significant difference in the thermo-emf in Al and In for H = 0. It is shown that the thermo-emf tensor Ŝ in a magnetic field H is determined by the competition between the two contributions ŜC and ŜU. The first of these contributions is associated with thermal diffusion and electron drag by a phonon wind in N-processes, and is calculated in terms of the electron and phonon heat capacities of the crystal. The second contribution is expressed in terms of the tensor components of resistance in a magnetic field and is associated with the electron drag by a phonon wind in U-processes.