Microwave Properties of Nb/PdNi/Nb Trilayers Observation of Flux Flow in Excess of Bardeen–Stephen Theory

• Published in: Journal of superconductivity and novel magnetism Vol. 26; no. 3; pp. 571 - 574
• Main Authors: Torokhtii, K., Pompeo, N., Meneghini, C., Attanasio, C., Cirillo, C., Ilyina, E. A., Sarti, S., Silva, E.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01-03-2013; Springer
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Exact sciences and technology; Magnetic Materials; Magnetic properties and materials; Magnetism; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Original Paper; Physics; Physics and Astronomy; Properties of type I and type II superconductors; Strongly Correlated Systems; Studies of specific magnetic materials; Superconductivity; Vortex lattices ,flux pinning, flux creep; Vortex dynamics; Dielectric resonator; S/F hybrids; Nb; Corbino disk; Electrical conductivity; Microwave radiation; Dielectric resonators; Magnetic field effects; Ferromagnetic materials; Vortex dynamic; Layer thickness; Multilayers; Cathode sputtering; Flux pinning; Wide band; Vortices; Corbino effect; Ultrahigh vacuum
• ISSN: 1557-1939; 1557-1947
• DOI: 10.1007/s10948-012-1795-7

We combine wideband (1–20 GHz) Corbino Disk and Dielectric Resonator (8.2 GHz) techniques to study the microwave properties in Nb/PdNi/Nb trilayers, grown by UHV dc magnetron sputtering, composed by Nb layers of nominal thickness
d
S
=15 nm, and a ferromagnetic PdNi layer of thicknesses
d
F
=1, 2, 8 and 9 nm. We focus on the vortex state. Magnetic fields up to
H
c2
were applied. The microwave resistivity at fixed
H
/
H
c2
increases with
d
F
, eventually exceeding the Bardeen–Stephen flux-flow value. Vortex pinning is very weak at large 
d
F
.