Vortex Dynamics in Ferromagnetic/Superconducting Bilayers
M.Z. Cieplak, Z. Adamus
Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland
M. Kończykowski
Laboratoire des Solides Irradiés, CEA/DSM/DRECAM and CNRS-UMR 7642, Ecole Polytechnique, 91128 Palaiseau Cedex, France
L.Y. Zhu and C.L. Chien
Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Md 21218, USA
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Received: 6 11 2007;
The dependence of vortex dynamics on the geometry of magnetic domain pattern is studied in the superconducting/ferromagnetic bilayers, in which niobium is a superconductor, and Co/Pt multilayer with perpendicular magnetic anisotropy serves as a ferrromagnetic layer. Magnetic domain patterns with different density of domains per surface area and different domain size, w, are obtained for Co/Pt with different thickness of Pt. The dense patterns of domains with the size comparable to the magnetic penetration depth (w ≥ qλ) produce large vortex pinning and smooth vortex penetration, while less dense patterns with larger domains (w ≫ λ) enhance pinning less effectively and result in flux jumps during flux motion.
DOI: 10.12693/APhysPolA.114.23
PACS numbers: 74.25.Ha, 74.25.Qt, 74.78.Db, 74.78.Fk