The theory of strong coupling superconductivity in disordered transition metal alloys

The equations of strong coupling superconductivity in disordered transition metal alloys have been derived by means of "irreducible" Green's functions and on the basis of the alloy version of the Barisic-Labbe-Friedel model for electron-ion interaction. The configurational averaging has been performed by means of the coherent potential approximation. Making some approximations, we have obtained the formulas for the transition temperature T sub(c) and the electron-phonon coupling constant lambda . These depend on the alloy component and total densities of states, the phonon Green's function, and the parameters of the model.