2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/17115It has been observed that the effect of magnetic impurities in a superconductor is drastically different depending on whether the host superconductor is in a crystalline or an amorphous state. Based on the recent theory of Kim and Overhauser, it is shown that as the system is getting disordered, the initial slope of the $T_{c}$ depression is decreasing by a factor $\sqrt{\ell/ξ_{0}}$, when the mean free path $\ell$ becomes smaller than the BCS coherence length $ξ_{0}$, which is in agreement with experimental findings. In addition, for a superconductor in a pure crystalline state the superconducting transition temperature $T_{c}$ drops sharply from about 50% of $T_{c0}$ (for a pure system) to zero near the critical impurity concentration. This {\sl pure limit behavior} was indeed found by Roden and Zimmermeyer in crystalline Cd.Revtex 16 pages, 6 figuresSuperconductivityMaterials Sciencetext