Investigation of Cu _0.5Ni _0.5/Nb interface transparency by using current-perpendicular-to-plane measurement

A direct determination of the interfacial transparency on the basis of current-perpendicular-to-plane (CPP) resistances for Cu _0.5Ni _0.5/Nb layered system is presented. This particular realization has substantial significance for understanding the interfacial transport in such heterostructures. The unexpected large critical thickness for this weak ferromagnetic containing system can be attributed to the strong pair-breaking effect as a result of the high interfacial transparency. Besides, the strong pair-breaking also plays a decisive role in the occurrence of the dimensionality crossover of the temperature dependent upper critical magnetic field.