Imprinted labyrinths and percolation in Nd-Co/Nb magnetic/superconducting hybrids

© 2014 AIP Publishing LLC. This work was supported by Spanish MINECO under grants FIS2008-06249 and Consolider CSD2007-00010 and by CAM under grant S2009/MAT-1726.
Magnetization reversal processes have been studied in hybrid magnetic/superconducting Nd-Co/Nb bilayers by the comparison of out-of-plane magnetic hysteresis loops and superconducting phase diagrams as a function of magnetic layer thickness and of disorder in the magnetic layer induced by a nanostructured copolymer template. A good correlation is found between the regimes corresponding to percolation effects in the superconductor and to the transition from extended to confined superconductivity with the characteristic fields for reverse domain nucleation and fast domain expansion in the magnetic layer, indicating that superconductivity nucleates on the disordered network imprinted on the superconducting layer by the labyrinth domain structure of the magnetic layer. As disorder increases in the magnetic layer, percolation effects disappear from the superconducting transitions in agreement with a more homogeneous magnetization reversal process.
MINECO
Comunidad de Madrid
Depto. de Física de Materiales
Fac. de Ciencias Físicas
TRUE
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