Influence of magnetic ordering on the superconducting properties of amorphous (Zr/sub 1-x/Er/sub x/)/sub 3/Rh alloys

The effect of Er impurities on the superconducting properties of an amorphous Zr/sub 3/Rh alloy has been studied. The Er impurities are found to exhibit magnetic behavior characteristic of a free Er/sup 3 +/ ion in a weak crystal field. Magnetic ordering of the Er moments is observed to occur at a temperature T/sub M/ which is proportional to the Er concentration. This ordering strongly influences superconductivity as evidenced by anomalous behavior in the concentration dependence of T/sub c/. For concentrations near the critical Abrikosov-Gor'kov value superconductivity appears to be induced by magnetic ordering. The superconducting critical field H/sub c2/(T) is strongly effected by magnetic ordering and can be used to deduce information concerning the nature of the ordering. The results are analyzed in terms of theoretical models