On the Explanation of the Paramagnetic Meissner Effect in Superconductor/Ferromagnet Heterostructures

Abstract

An increase of the magnetic moment in superconductor/ferromagnet (S/F) bilayers V(40nm)/F [F$=$Fe(1,3nm), Co(3nm), Ni(3nm)] was observed using SQUID magnetometry upon cooling below the superconducting transition temperature Tc in magnetic fields of 10 Oe to 50 Oe applied parallel to the sample surface. A similar increase, often called the paramagnetic Meissner effect (PME), was observed before in various superconductors and superconductor/ferromagnet systems. To explain the PME effect in the presented S/F bilayers a model based on a row of vortices located at the S/F interface is proposed. According to the model the magnetic moment induced below Tc consists of the paramagnetic contribution of the vortex cores and the diamagnetic contribution of the vortex-free region of the S layer. Since the thickness of the S layer is found to be 3-4 times less than the magnetic field penetration depth, this latter diamagnetic contribution is negligible. The model correctly accounts for the sign, the approximate magnitude and the field dependence of the paramagnetic and the Meissner contributions of the induced magnetic moment upon passing the superconducting transition of a ferromagnet/superconductor bilayer.

References in corpus (3)

• Magnetic proximity effects in V/Fe superconductor/ferromagnet single bilayer revealed by waveguide-enhanced polarized neutron reflectometry
• Magnetic State Modification Induced by Superconducting Response in Ferromagnet/Superconductor Hybrids
• Direct observation of nanometer-scale pinning sites in (Nd${}_{0.33}$,Eu${}_{0.20}$,Gd${}_{0.47}$)Ba${}_2$Cu${}_3$O${}_{7-\delta }$ single crystals

Cited by in corpus (3)

• Inverse magnetic hysteresis of the Josephson supercurrent: study of the magnetic properties of thin niobium/permalloy (Fe_{20}Ni_{80}) interfaces
• Giant electromagnetic proximity effect in superconductor/ferromagnet superlattices
• Absence of magnetic interactions in Ni-Nb ferromagnet-superconductor bilayers