Negative magnetoresistance produced by Hall fluctuations in a ferromagnetic domain structure

摘要

We present a model for a negative magnetoresistance (MR) that would develop in a material with many ferromagnetic domains even if the individual domains have no magnetoresistance and even if there is no boundary resistance. The negative MR is due to a classical current-distortion effect arising from spatial variations in the Hall conductivity, combined with a change in domain structure due to an applied magnetic field. The negative MR can exceed 1000 if the product of the carrier relaxation time and the internal magnetic field due to spontaneous magnetization is sufficiently large.