On the explanation of the paramagnetic Meissner effect in superconductor/ferromagnet heterostructures

Research output: Contribution to journalArticle

Abstract

An increase of the magnetic moment in superconductor/ferromagnet (S/F) bilayers V(40 nm)/F (, Co(3 nm), Ni(3 nm)) was observed using SQUID magnetometry upon cooling below the superconducting transition temperature T C 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 T C 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.

Details

Authors
  • B Nagy
  • Yu Khaydukov
  • Dimitar Efremov
  • A. S. Vasenko
  • L. Mustafa
  • H. -J. Kim
  • Evan T. Keller
  • K. Zhernenkov
  • A. Devishvili
  • R. Steitz
  • B. Keimer
  • L. Bottyán
External organisations
  • Linköping University
  • Hungarian Academy of Sciences
  • Max Planck Institute for Solid State Research
  • Leibniz Institute for Solid State and Materials Research
  • Ruhr-University Bochum
  • Helmholtz-Zentrum Berlin for Materials and Energy
  • National Research University Higher School of Economics, Moscow
  • Lund University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Condensed Matter Physics
Original languageEnglish
Article number17005
JournalEurophysics Letters
Volume116
Issue number1
Publication statusPublished - 2016 Oct 1
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes