Zur anschaulichen Diskussion der qualitativen Eigenschaften der galvanomagnetischen Koeffizienten

Abstract

The dependence of the different components of the conductivity resp. the resistivity tensor upon the strength and direction of an external magnetic field is discussed qualitatively. — In metals, in which the Fermi surface is simply closed, the changes in longitudinal and transversal resistance and the Hall coefficients are large if the anisotropies of the Fermi surface resp. of the scattering mechanism in the planes perpendicular to magnetic field direction are large, and vice versa. In fields, in which this effect already clearly is marked, the changes in transversal resistance in addition increase with increasing anisotropies ink-space perpendicular to Hall field direction, whereas by equal set in of current and Hall field direction the Hall coefficients now show a tendency to decrease with increasing anisotropies perpendicular to magnetic field direction. The order of Hall coefficients may change in high magnetic fields. In contrast to the changes in resistance the Hall coefficients decrease with increasing strength of magnetic field. — In the presence of open Fermi surfaces the transversal resistance doesn't saturate in the direction of the open orbits. If open orbits exist in more than one direction, saturation returns and the Hall coefficients now vanish proportional to 1/B 2. In considering open Fermi surfaces it is not allowed to neglect scattering in strong magnetic fields.