Hall Effects and Magnetoresistance in Some Nickel-Copper-Iron Alloys

Abstract

The ordinary and extraordinary Hall coefficients and transverse magnetoresistance of six Ni-Cu-Fe alloys have been measured in the temperature range of 20°K to room temperature. All six alloys contain nominally 70 at.% Ni, with Cu and Fe additions to provide electrons concentrations from 27.7 to 28.2 electrons per atom. The ordinary Hall coefficient is found: (i) to be insensitive to electron concentration; (ii) to vary with temperature in the way predicted by the 4-band model; (iii) to have a magnitude consistent with the 4-band model if anisotropic electron scattering is assumed. The extraordinary Hall coefficient is positive for the alloys with 27.7, 27.8, 27.9, and 28.0 electrons per atom, and negative for the alloys with 28.1 and 28.2 electrons per atom. The transverse magnetoresistance shows the typical behavior of ferromagnetic alloys, except that the resistance does not vary linearly with the magnetic induction above saturation. The reduced ideal resistivity is found to be a universal function of a reduced temperature for these six alloys and Ni.