T-matrix calculation of itinerant-electron ferromagnetism in off-diagonal disordered alloys

The transverse spin current susceptibility of disordered Hubbard ferromagnets is examined employing a Bethe-Salpeter-like equation. A magnon scattering contribution to the spin wave stiffness coefficient is deduced by averaging out off-diagonal disorder in the additive limit. Self-consistent numerical solutions of the coherent ladder approximation are presented in the ferromegnetic case for densities of states, self-energies, and local two-particle T-matrices. The application to NiPt alloys brings out the effects of electron correlations and random hopping integrals. (author)