PINNING IN PROXIMITY COUPLED SUPERCONDUCTING NORMAL METAL MULTILAYERS/

Measurements have been made of the critical current density, J(c), in sputtered Nb/CuX multilayers where CuX is either pure Cu, CuGe(2%), Cu Ge(10%), or CuMn(0.3%). The effects on the pinning force, F-p = J(c) x B, due to the addition of Ge (non-pairbreaking) or Mn (pairbreaking) impurities in the normal metal is investigated with two sample orienta tions. The interpretation of this data attempts to discriminate betwee n the effects of pinning at the interfaces and pinning which arises fr om the impurities in the normal metal.