Meissner or Flux pinning?

Qualitative Experiment steps:

Quantum Levitation is the stable levitation and suspension of a superconductor in a surrounding magnetic field. It is actually the result of two separate phenomena:

• Meissner effect – the repulsion of magnetic fields from the superconductor body
• Flux pinning – the pinning of magnetic flux inside the superconductor

We can perform the following experiments to distinguish between the two –

Meissner effect:

1. Take a Quantum Levitator and place it upside down, with the superconductor at the bottom facing up.
2. Cool with liquid nitrogen. Make sure not to over fill the nitrogen liquid.
3. Take a small magnet (like this) and gently drop it a few inches/cm above the superconductor.
4. It will jump right up, being repelled from the superconductor. This is perfect diamagnetism caused by the Meissner effect.
   

Flux pinning:

1. Repeat the same setup with the levitator upside down and cooled.
2. This time, push the magnet using plastic tweezers closer to the superconductor. Make sure to push the magnet close enough to feel the resistance.
3. Now, when you release the magnet – it stays floating, rotating around its symmetry axis.

Quantitive experiment:

Get actual numbers and analyze the forces – repulsion and attraction, between a superconductor and a magnet. With the Superconductivity Experiment kit you can measure and record the actual forces in different scenarios:

SUPERCONDUCTIVITY EXPERIMENT KIT