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

Abstract

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 ${\rho }_{ff}$, that we access at subcritical currents using a sufficiently high driving frequency. We find that ${\rho }_{ff}$ 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.

4 pages, 3 figures

References in corpus (2)

• Reliable determination of vortex parameters from measurements of the microwave complex resistivity
• Wideband microwave measurements in Nb/Pd${}_{84}$Ni${}_{16}$/Nb structures and comparison with thin Nb films

Cited by in corpus (5)

• Thermodynamic nature of the 0-PI quantum transition in superconductor-ferromagnet-superconductor trilayers
• Robustness of the $0-\pi$ transition against compositional and structural ageing in S/F/S heterostructures
• First order $0$ - $\pi$ phase transitions in superconductor/ferromagnet/superconductor trilayers
• Microwave properties of Nb/PdNi/Nb trilayers. Observation of flux flow in excess of Bardeen-Stephen theory
• Analysis of the measurements of anisotropic a.c. vortex resistivity in tilted magnetic fields