Scattering-Center Effects in the Magnetoresistance of Nickel

Publisher Website
Google Scholar
Abstract
The magnetoresistance of many polycrystalline samples of nickel alloyed with small concentrations of iron, cobalt, manganese, chromium, and carbon has been measured. An analysis of the data gave the result that all those specimens in which the conduction-electron scattering was dominated by one particular scattering center were found to obey Kohler's rule. However, the details of the magnetoresistance were different in each case, with the exception of the iron, cobalt, and manganese impurities, which formed one group. In addition, the thermal-scattering magnetoresistance and that due to deformation were different again. These observations confirm previous conclusions concerning the validity of Kohler's rule. Extremely large magnetoresistance was found for the iron, cobalt, and manganese group of impurities as scattering centers, which apparently is much larger than observed in any other system. This can be correlated with other electronic properties of the impurities, such as the resistivity and magnetic moment per unit concentration. In particular, the high magnetoresistance appears associated with the presence of large local moments. The zero-field anisotropy in the resistance is also correlated with these same properties. In spite of this correlation, we have no clear interpretation of the extreme magnetoresistance.