SOME PROBLEMS CONCERNING TC DEPRESSION OF NON-TRANSITION ELEMENT SUPERCONDUCTORS DOPED WITH 3D-TRANSITION ELEMENT IMPURITIES

A critical discussion of the measurements of the Tc depression of superconductors doped with 3d-element impurities is given under metallurgical aspects. Particularly, the formation of binary solid solutions in these systems is investigated. The contradictions between thin film and bulk material work are removed by showing that metallurgical difficulties connected with the sample preparation have led to incorrect interpretation of the results. Furtheron it is shown that an exact proof of the Abrikosov-Gorkov theoretical dependence of the critical temperature versus concentration has so far not been given. © 1969 Springer-Verlag.