Effect of Oxygen on the Magnetoresistance of Copper

To determine the influence of physical and/or chemical impurities on the high field magnetoresistance of copper, measurements were made of the effect on specimen properties of work hardening and the presence of ${\mathrm{O}}_2$ in the atmosphere used for annealing. A Kohler plot of the transverse magnetoresistance for all specimens gave a single smooth curve. The plot for the longitudinal magnetoresistance of any one specimen as the concentration of defects was increased between successive measurements, also gave a smooth curve. However, the saturation value of the longitudinal magnetoresistance was markedly affected by annealing in an atmosphere containing ${\mathrm{O}}_2$. The zero field ratio of transverse to longitudinal magnetoresistance was found to be quite insensitive to work hardening and the presence of ${\mathrm{O}}_2$ in the annealing atmosphere.