Crossover between different regimes of inhomogeneous superconductivity in planar superconductor-ferromagnet hybrids

We studied experimentally the effect of a stripelike domain structure in a ferromagnetic BaFe12O19 substrate on the magnetoresistance of a superconducting Pb microbridge. The system was designed in such a way that the bridge is oriented perpendicular to the domain walls. It is demonstrated that depending on the ratio between the amplitude of the nonuniform magnetic field B-0, induced by the ferromagnet, and the upper critical field H-c2 of the superconducting material, the regions of the reverse-domain superconductivity in the H-T plane can be isolated or can overlap (H is the external magnetic field, T is temperature). The latter case corresponds to the condition B-0/H-c2 < 1 and results in the formation of superconductivity above the magnetic domains of both polarities. We discovered the regime of edge-assisted reverse-domain superconductivity, corresponding to localized superconductivity near the edges of the bridge above the compensated magnetic domains. Direct verification of the formation of inhomogeneous superconducting states and external-field-controlled switching between the normal state and inhomogeneous superconductivity were obtained by low-temperature scanning laser microscopy.

Publication year:2011

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BOF-publication weight:2

CSS-citation score:1

Authors:International

Authors from:Higher Education

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