Galvanomagnetic effects in metals with closed Fermi surfaces in intermediate magnetic fields

Low-temperature magnetoresistivity in metals with a closed Fermi surface is considered for the case when the relaxation processes are determined by electron-phonon interactions. In the situations studied the probability of Umklapp processes is appreciable either in the neighborhood of some isolated “hot” spots (Sec. 1), near certain lines, or within some regions covering a significant part of the Fermi surface (Sec. 2). In the latter case an important role may be played by the mechanism of “magnetic Umklapp” diffusion which forms effective electron orbits over a wide range of magnetic fields that are significantly different from those in a strong magnetic field. In particular, the effective orbits can be open or hole-type for a closed electron Fermi surface. The existence of a region of intermediate magnetic fields is shown to be a typical situation not associated with any specific feature of the Fermi surface although the width of this region and the behavior of transverse resistivity in it do depend essentially on the temperature range and the features of the electron spectrum of the particular metal.