Strong and weak electron spin-orbit scattering near the metal-insulator transition

A detailed comparison of two disordered alloys, GeₓAu_1-x and BₓCu_1-x, is carried out near their metal-insulator transition. In zero magnetic field these two materials have approximately linear mobility edges and similar temperature-dependent dc conductivity behaviors. However, the magnetoresistance is dramatically different in high fields for these two materials in spite of similar electron inelastic scattering times. This difference is attributed to the different spin-orbit scattering in these two materials.