Sharpening of the resistive transition of a superconductor with the addition of paramagnetic impurities

We present evidence demonstrating that the addition of magnetic moments to a superconductor suppresses the Maki-Thompson contribution to the fluctuation conductivity. Measurements of the resistive transition of aluminum films with erbium impurities exhibit a sharpening of the transition with increasing impurity concentration which can be explained quantitatively using Thompson's scheme for regularizing the Maki-Thompson conductivity diagrams.