Vortex motion in Nb/PdNi/Nb trilayers: New aspects in the flux flow state

• Published in: Physica. C, Superconductivity Vol. 479; pp. 140 - 142
• Main Authors: TOROKHTII, K, ATTANASIO, C, CIRILLO, C, ILYINA, E. A, POMPEO, N, SARI, S, SILVA, E
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Amsterdam Elsevier 01-09-2012
• Subjects: Computational fluid dynamics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Ferromagnetism; Fluid flow; Mathematical models; Multilayers, superlattices , heterostructures; Niobium; Physics; Properties of type I and type II superconductors; Superconducting films and low-dimensional structures; Superconductivity; Superconductors; Temperature dependence; Vortex lattices ,flux pinning, flux creep; Vortices; Surface impedance; Flux line; Electrical conductivity; Nickel alloys; Dielectric resonator; Ginzburg-Landau theory; Ferromagnetic materials; Niobium; Thin films; Time dependence; Superconductors; Vortex dynamics; Investigation method; Nb; Palladium alloys; Transition elements; Vortex motion; S/F hybrids; Corbino disk; Subcriticality; Heterostructures; Transition element alloys
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/j.physc.2011.12.011

We study the dynamics of vortex lines in Supercondutor/Ferromagnet/Superconductor (SFS) heterostructures at microwave frequencies. We have employed swept-frequency, Corbino-disk and resonant, dielectric-resonator techniques to obtain the field and temperature dependence of the vortex-state parameters. We concentrate here on the genuine flux-flow resistivity ?ff, that we access at subcritical currents using a sufficiently high driving frequency. We find that ?ff does not follow the well-known Bardeen-Stephen model. Instead, it is well described by a full time-dependent Ginzburg-Landau expression at very thin F layer thickness, but changes to a previously unreported field-dependence when the F layer exceeds a few nm.