The electrical resistivity of nickel and its alloys

Abstract

The electrical resistivity has been measured over the temperature range 1 °K to 120 °K in dilute alloys of nickel with Pd, Cu, Co, Fe, Mn, Cr, V and Ti. The impurity (residual) resistivity is very small for alloys of nickel with its near neighbours in the periodic table, Pd, Cu, Co, Fe and Mn, but is an order of magnitude greater for alloys containing Cr, V and Ti. The ice-point values of the deviations from Matthiessen's rule are unusually large in the Ni-Co, Ni-Fe, Ni-Mn, and Ni-Cr alloys, somewhat smaller in the Ni-Cu, Ni-V and Ni-Ti alloys, and negligible in Ni-Pd. These results are interpreted on the assumption that the departures from Matthiessen's rule arise because of spin mixing between electrons in the spin downward arrow and spin upward arrow bands. On this basis it has proved possible to separate the two components of impurity resistivity for the two spin directions. The values obtained correlate well with the known band structure and impurity states of nickel and its alloys. In addition, the temperature dependence of the deviations in all the measured alloys can be explained on the basis of spin mixing, with the only adjustable parameter being capital Lambda, Greek(upward arrowdownward arrow), the mean free path between spin flips.