Magnetoresistance of copper

Abstract

The magnetoresistance of copper has been measured at 297, 78 and 4.2°K. In a transverse field of 100 kG at room temperature, the resistance increased about 1 4 per cent and, within experimental error, was a quadratic function of the applied magnetic field. At the lower temperatures the field-dependence of the transverse magnetoresistance is considerably less than quadratic and approaches linearity at high fields. Considerable temperature-dependence for Kohler's rule was found. Saturation of the longitudinal magnetoresistance at high fields was observed at 4.2°K. The change in longitudinal resistance for saturation is of the order of the initial resistance in zero field and was found to be independent of temperature for the range 2.0–4.2°K and of measuring current for the range 0.1–2.0 A. The ratio of the transverse to the longitudinal magnetoresistance of a specimen was found to be a linear function of the applied field. These new features of magnetoresistive behavior can serve to stimulate the development of an adequate theory of longitudinal and transverse magnetoresistance.