Critical fields ofFe4N/NbN ferromagnetic/superconducting multilayers

Abstract
Structural, magnetic, and superconducting properties of ferromagnetic/superconducting multilayers of Fe4N/NbN are explored for a variety of thickness combinations. The superconducting properties show that 11 Å ferromagnetic layers are sufficient to decouple the superconducting layers and to yield anisotropic behavior. The upper critical field data are well described by theory for ferromagnetic/superconducting multilayers. This analysis yields an interfacial parameter which characterizes the electron scattering at the ferromagnetic/superconducting boundary.