Transport characteristics of a superconductor–ferromagnet composite

Abstract

The transport properties of a composite consisting of the microparticles of superconductor MgB2 and nanopowder of manganite La0.7Sr0.3MnO3 (LSMO) were studied. It was found that when the amount of the ferromagnet component in the composite was above 10% by volume, a sharp increase in the resistivity of the composite occurred. This is caused by the disruption of percolation paths through the magnesium diboride microparticles, thus leading to the formation of a network of superconductor-ferromagnet-superconductor junctions. As a result, a significant broadening of the superconducting transition of the composite was observed while its ferromagnetic properties were maintained. The obtained data indicate that Cooper pairs can pass through the layer of a half-metal ferromagnet with high (about 100%) spin polarization of the charge carriers and thickness d > 10 nm.

Half-metallic double perovskite oxides: recent developments and future perspectives

“…Kalcheim et al 240 epitaxially grew LCMO films on superconducting Pr 1.85 Ce 0.15 CuO 4 , and they found a long-range penetration of superconductivity into the HM LCMO by scanning tunneling spectroscopy. Kononenko et al 241 also investigated the transport properties of composites consisting of MgB 2 superconductor microparticles and La 0.7 Sr 0.3 MnO 3 (LSMO) manganite nanopowders. They found that the disruption of the percolation path through the MgB 2 particles caused the resistivity of the composite to increase, resulting in a network of SFS junctions.…”