Saturating and linear magnetoresistive effects in sodium and potassium

The theoretically predicted and long-sought intrinsic saturation of the transverse magnetoresistance of the alkali metals has finally been observed after sufficiently reducing the masking effect of the large superimposed linear magnetoresistance which is attributed to such classical considerations as geometry, Hall angle and non-uniform current distribution. The observed saturation values were about 100 times smaller than those observed previously in complicated metals but were still much too large to be explained only by Fermi surface anisotropy. The saturation phenomena contradict Kohler's rule but can be plausibly explained by mean free path anisotropy due predominantly to electron-phonon scattering mechanisms.