Transverse magnetoresistance of oxygen-free copper

Recent studies on the magnetoresistance of copper with residual resistance ratios (RRR) in the range 100-1000, and using cold work and irradiation as parameters modifying RRR, show a large spread when presented on a Kohler plot. Results of 4 K magnetoresistance measurements on a large number of samples of copper from various sources and in various states of cold work, strain, and reanneal are presented and discussed. The RRR values range from 48 to 655; all tempers are represented. The results shown suggest that use of Kohler plot data taken at 4 K to predict magnetoresistance at much higher temperatures (such as 76 K) is probably not a reliable practice.<>