Superconducting and Structural Properties of Nb/PdNi/Nb Trilayers

• Published in: Journal of superconductivity and novel magnetism Vol. 26; no. 5; pp. 1939 - 1943
• Main Authors: Pompeo, N., Torokhtii, K., Meneghini, C., Mobilio, S., Loria, R., Cirillo, C., Ilyina, E. A., Attanasio, C., Sarti, S., Silva, E.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01-05-2013; Springer
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Disorders; Exact sciences and technology; Fluid flow; Magnetic Materials; Magnetic properties and materials; Magnetism; Microwaves; Niobium; Original Paper; Physics; Physics and Astronomy; Pinning; Properties of type I and type II superconductors; Strongly Correlated Systems; Studies of specific magnetic materials; Superconducting materials (excluding high-tc compounds); Superconductivity; Superconductors; Vortex lattices ,flux pinning, flux creep; Vortices; Superconductor/Ferromagnet heterostructures; Local structure; Vortex pinning; Superconductivity; Ferromagnetic materials; Layer thickness; Microwave measurement; Fine structure; Multilayers; Superconductors; Flux pinning; X-ray absorption spectra; Heterostructures
• ISSN: 1557-1939; 1557-1947
• DOI: 10.1007/s10948-012-2057-4

The superconducting and structural properties of S/F/S (Superconductor/Ferromagnet/Superconductor) heterostructures have been studied by means of microwave measurements (1–20 GHz) and x-ray absorption fine structure (XAFS) spectroscopy. Nb/PdNi/Nb trilayers have been studied as a function of F layer thickness. With respect to pure Nb, XAFS analysis shows that the heterostructures exhibit larger structural disorder in the S layers. Microwave measurements show evidence for a progressively weaker vortex pinning with increasing F thickness. However, no clear correlation is found with the local disorder in Nb: the weakest pinning is not in the most disordered trilayer. Therefore, the structural disorder in the superconducting material cannot explain on its own the changes in vortex pinning. We argue that the F layer acts on the superconducting state itself. We propose possible explanations for the observed behavior.