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

The effect of Er impurities on the superconducting properties of an amorphous Zr3Rh alloy was studied. The Er impurities were foundt o exhibit magnetic behavior characteristic of a free Er(3+) ion in a weak crystal field. Magnetic ordering of the Er moments was observed to occur at a temperature T/sub M/ which is proportional to the Er concentration. This ordering strongly influenced superconductivity as evidenced by anomalous behavior in the concentration dependence of T/sub c/. For concentrations near the critical Abrikosov-Gorkov value superconductivity appeared to be induced by magnetic ordering. The superconducting critical field H/sub c2/(T) was strongly effected by magnetic ordering and could be used to deduce information concerning the nature of the ordering. The results are analyzed in terms of theoretical models.