AIP Advances (Oct 2017)

Advanced magneto-optical Kerr effect measurements of superconductors at low temperatures

  • Claudia Stahl,
  • Joachim Gräfe,
  • Stephen Ruoß,
  • Patrick Zahn,
  • Jonas Bayer,
  • Julian Simmendinger,
  • Gisela Schütz,
  • Joachim Albrecht

DOI
https://doi.org/10.1063/1.4985044
Journal volume & issue
Vol. 7, no. 10
pp. 105019 – 105019-7

Abstract

Read online

Magneto-optical Kerr-effect (MOKE) measurements of superconducting films with soft-magnetic coatings are performed at low temperatures using a laser-based MOKE set-up. An elaborate measurement scheme with internal reference allows the quantitative comparison of the temperature dependent Kerr-amplitude with the magnetic field generated by supercurrents. For this purpose, an amorphous CoFeB thin film exhibiting a large Kerr-signal is deposited directly on top of the YBCO superconductor acting as field sensing layer. It is shown that the resulting magnetic hysteresis loops of the soft-magnetic film can be used to reconstruct the electric properties of the superconductor.