CONSIDERATIONS ON SUPERCONDUCTORS CONTAINING NONMAGNETIC TRANSITION-METAL IMPURITIES

The effect of nonmagnetic transitional impurities on the superconducting critical temperature of nontransition metals is studied. With a slightly modified BCS method a result is found which is shown to be valid more generally. The critical temperature is given by an equation which separates the effect of the impurities on the electron states paired together from that due to the change in the interaction between the two mates of a pair. Our formulae are then compared with experimental results for the Al-base alloys, which seem to confirm the contribution of the localized spin fluctuations in AlMn. © 1969 Società Italiana di Fisica.