Free electron scattering on a localised potential with cubic symmetry: application to AuNi

Abstract

The authors have calculated the resistivity, caused by the scattering of free electrons on an impurity described by a localised potential with cubic symmetry in terms of phase shifts (l<or=2), using an exact solution of the linearised Boltzmann equation and an approximation to the solution consisting of four cubic harmonics with t1z symmetry. The latter approach is based on the variational principle, whereas the former one is developed along the lines indicated by Mertig and co-workers (1982). The resistivity calculated with the exact solution still contains three numerical integrals, which have to be computed for every set of scattering phase shifts. The resistivity calculated with the approximation implies an inversion of a symmetric 4*4 matrix for each set of phase shifts. The resistivity calculated with the approximation deviates markedly only for some sets of phase shifts from the resistivity calculated with the exact solution. The phase shifts, deduced from recent UPS measurements on AuNi, cannot account for the experimental resistivity within the model.