Effect of the Self-Magnetic Field on Galvanomagnetic Effects in Bismuth

The magnetoresistance and the Hall coefficient for pure bismuth at 77°K have been calculated to the second order in the self-magnetic field, i.e. current density. The calculations show that the observed dependence of the galvanomagnetic effects on the current density at high currents can be qualitatively explained by the self-magnetic field. However, to obtain quantitative agreement it is necessary to include the contribution of diffusion currents in the calculation. The theory for the self-magnetoresistance, including diffusion, has been carried out for the pre-pinch regime of currents. The resulting curve for the self-magnetoresistance agrees well with the observed one if the scattering times between ellipsoids are taken to be of order 10
⁻⁹
sec (assuming that the diffusion effects are not dominated by the surface, i.e. that the surface-recombination velocity is sufficiently small).