Superconducting and structural properties of Nb/Ni multilayers

Multilayers of Nb/Ni have been fabricated by magnetron sputtering technique. Diffraction patterns show a good multilayer structure. The Ni layers induce superconducting critical temperatures lower than the expected taking into account only metallic proximity effect. The upper critical magnetic fields measurements allow us to extract a superconducting coherence length perpendicular to the layers of the order of 27 A.