Dependence of electrical resistivity on the degree of short range order in a nickel–copper alloy

Abstract

The simultaneous measurement of the residual electrical resistivity and the diffuse neutron scattering supplies the experimental foundation for an analysis of the effects of atomic distribution in a binary alloy on the electrical resistivity. Using the Warren–Cowley short-range order (SRO) parameters of Ni–41·4 at.% Cu as derived from the diffuse neutron scattering for various SRO states corresponding to temperatures between 380 K and 730 K, the resistivity contribution of the alloy due to short-range order is calculated according to the theoretical formalism of Rossiter and Wells. By comparison with the experimental resistivity data it is shown that, for the investigated temperature range, the above formalism accounts quantitatively for the dependence of the electrical resistivity on the degree of short-range order. The main contribution to the resistivity was found to result from the atomic distribution in the first coordination shell. The present work confirms experimentally corresponding assumptions made earlier in interpreting resistivity measurements in terms of changes of the atomic distribution.