MACROSCOPIC INHOMOGENEITIES AND THE MAGNETORESISTANCES OF THE SIMPLE METALS

We have determined the effects of large-scale voids on the high-field thermal magnetoresistance of simple metals, including the effects of the lattice conductivity. The calculations were performed by a Green's function approach and by a boundary-value method. We find that the presence of the lattice conduction causes large deviations from the linear term evident in the electrical magnetoresistivity. The thermal magnetoresistivity, both transverse and longitudinal, saturates in sufficiently strong fields. The deviation from linearity occurs for 10≤ωcτ≤100 depending upon the magnitude of kg. The Righi-Leduc coefficient is determined and it is found that the voids cause a slight increase. The magnetoresistance anomalies of potassium cannot be explained by the presence of voids. © 1979 The American Physical Society.