Magnetoresistance of Single Crystals of Copper

Abstract

Measurements of the magnetoresistance coefficients at 4.2° K and at 20.4° K in single crystals of copper, silver, and gold in the low magnetic field range, and in single crystals of silver for high magnetic field are reported. The low-field results were analyzed under the assumptions that a relaxation time exists and is a function of the energy alone, and that the Fermi surface is a single closed surface within the first Brillouin zone and not touching its boundary. It is found that for copper the magnetoresistance cannot be fitted very well on this model. We assume that at low temperature the hypothesis that a relaxation time exists is a good approximation, and suggest that in copper the Fermi surface touches the boundary of the first Brillouin zone. The magnetoresistance of silver in high magnetic fields shows marked anisotropy and no sign of saturation.