Diffusion Size Effect in Bismuth

抄録

The galvanomagnetic properties of thin bismuth samples have been found to exhibit some strong dependences on sample size at 77°K, involving a reduction in the transverse magnetoresistance and Hall coefficient with decreasing thickness. It has been shown theoretically and experimentally that this size-effect is related to the diffusion length rather than to the mean free path. Comparison of experiments with theory gives a value for the effective electron lifetime, τ∼4×10⁻¹⁰ sec. The magnetic field dependence of the transverse magnetoresistance is also discussed.