5G50.50 High Tc Superconductor




A NdBFe magnet levitates above a high Tc superconductor when it is superconducting. Note: with the video camera, this demonstration is appropriate for large lecture halls.



  • [1] High Tc YBaCuO superconductor with a piece of yellow tape affixed to the top surface (for visibility)
  • [1] Small NdBFe magnet
  • [1] Petri dish
  • [1] Foam support
  • [1] Pair of plastic forceps
  • [1] Small wire hoop
  • [1] Foam cup
  • [1] Video camera
  • [1] Small (~2L) dewar of liquid nitrogen

Safety Equipment

  • [1] Safety goggles
  • [2] Safety glove

Classroom Assembly

  1. Place the petri dish on the foam support.
  2. Place the superconductor in the petri dish.
  3. Center the NdBFe manget on the superconductor using the forceps.

Important Notes

  • Liquid nitrogen can cause severe burns and blindness. Use with caution.
  • The magnet is strong. Handle with care.
  • The superconductor is brittle. Handle with care.


  1. Pour liquid nitrogen into the petri dish until the superconductor is fully submerged. WEAR APPROPRIATE SAFETY GEAR.
  2. Continue to add liquid nitrogen as it boils off. When the superconductor reaches critical temperature (~90K), it will superconduct and the magnet will levitate. Be patient; this can take a while.
  3. Spin the magnet with the forceps.
  4. Pass the wire hoop around the magnet to show it is levitating.
  5. Gently push the magnet with the forceps to demonstrate its range of stability over the superconductor.


Additional Resources


  • PIRA 5G50.50


  • Don't attempt this at home!

Last revised

  • 2018


Related AV

Related demos

  • Wire Coil in Liquid Nitrogen


If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.