Effective electric conductivity tensor of polycrystalline metals in high magnetic fields

Abstract

General equations with unknown parameters are obtained for the effective electric conductivity tensor of polycrystalline mixtures. Different methods of obtaining the unknown parameters are discussed. One of these methods, called in the paper the Bruggeman-Odelevsky method, has been applied to polycrystalline metals in a magnetic field. The influence of three different factors 1) fluctuations of the electron density 2) open orbits, 3) extended orbits, on the galvanomagnetic properties of a polycrystal has been investigated. In the first case agreement is found with Herrng's results, although it is shown that the range of applicability of his method is very restrained. The second case has not been considered by other authors. In the third case it is shown that the averaging method used by earlier authors needs very strong assumptions and this makes their explanation of the linear growth of the magnetoresistance doubtful.