Nonrelativistic phase-shift analysis of impurity scattering in noble-metal hosts

A general framework is developed for the self-consistent analysis of experimental measurements of quasiparticle scattering by dilute substitutional impurities in metallic hosts. The development is based on phase-shift analysis in the muffin-tin approximation, and departures from free-electron behavior in the host lattice are taken into account. Expressions are given for the Dingle-temperature anisotropy, the impurity resistivity, and the Friedel sum. These quantities depend upon scattering coefficients of the host metal, and on a set of effective ("Friedel") scattering phase shifts. The scattering coefficients for $s$-, $p$-, and $d$-wave scattering in noble-metal hosts are calculated from wave functions determined from nonrelativistic Korringa-Kohn-Rostoker (KKR) phase-shift parametrizations of their Fermi-surface anisotropies. The Friedel phase shifts are determined from analyses of the Dingle-temperature anisotropies and residual resistivities of a series of alloys of nonmagnetic impurities in noble-metal hosts. The Friedel phase shifts are independent of the choice of the Fermi-energy parameter in the phase-shift analysis, and are found to be consistent with the Friedel sum rule whenever lattice distortions and spin-orbit effects can be neglected.