New resistance anomaly in the superconducting fluctuation region of disordered Cu-Zr alloys with dilute magnetic impurities

In disordered superconducting Cu-Zr alloys with dilute magnetic impurities, we have observed a new type of resistance anomaly which gives rise to strongly increased scattering of conduction electrons in a narrow temperature range above Tc and appears to be due to interaction between superconducting fluctuations and spin. For a given level of impurities this phenomenon is peaked around Cu₅₀{Zr}₅₀$, but is observable from 36 to 60 at.% Zr. When the Cr impurity concentration is varied in ${Cu}₅₀Zr₅₀, a resistance peak can be observed for 100--600 ppm Cr with a maximum peak height of about 6% of the measured resistance. The effect is destroyed by a magnetic field of some tenths of a tesla.