Anisotropic S-wave superconductors containing transition metal impurities: High T-k Kondo impurities

The effects of transition metal impurities whose magnetic behavior is that of high T-K Kondo impurities and of anisotropy on the T-c's of conventional superconductors are studied within the framework of the strong coupling Eliashberg formalism. The Matsuura-Ichinose-Nagaoka theory is used to describe the high T-K Kondo impurities. It is shown that the strong coupling and anisotropy combine to change the magnitudes of the initial decrease in T-c due to the impurities and of the critical concentration at which the impurities completely suppress superconductivity in different ways. The value of the former is lowered while the value of the latter is raised.