Meissner effect

Definition

The Meissner effect is the expulsion of a magnetic field from a superconductor when it transitions below its critical temperature, resulting in perfect diamagnetism. This phenomenon demonstrates that superconductors are not merely perfect conductors but have unique magnetic properties.

5 Must Know Facts For Your Next Test

1. The Meissner effect occurs when a material becomes superconducting below its critical temperature.
2. It causes the superconductor to exhibit perfect diamagnetism, meaning it will expel all internal magnetic fields.
3. The effect distinguishes superconductors from perfect conductors, which do not expel magnetic fields in the same way.
4. The Meissner effect can be observed through magnetic levitation experiments, such as with a superconductor and a small magnet.
5. The mathematical description of this effect involves the London equations, which explain how electromagnetic fields behave in superconductors.

Review Questions

• What happens to the magnetic field inside a material when it undergoes the Meissner effect?
• How does the Meissner effect differentiate superconductors from perfect conductors?
• Which physical phenomenon can visually demonstrate the Meissner effect?

Related terms

Critical Temperature: The temperature below which a material becomes superconducting and exhibits phenomena like the Meissner effect.

Diamagnetism:

A form of magnetism where materials are repelled by external magnetic fields; exhibited perfectly by superconductors due to the Meissner effect.

London Equations:

A set of equations that describe electromagnetic properties of superconductors, including their response to applied magnetic fields.