demonstrations:magnetic_levitation_with_pyrolytic_graphite

Magnetic Levitation with Pyrolytic Graphite

Materials: ★★★ Requires materials not commonly found in school laboratories
Difficulty: ★★★ Requires a more experienced teacher
Safety: ★★☆ Some safety precautions required to perform safely

Categories: Magnetism

Alternative titles: Diamagnetism of Pyrolytic Graphite

Summary

Pyrolytic graphite is a strongly diamagnetic material that can levitate above neodymium magnets. It also conducts heat efficiently, allowing it to melt through ice easily by transferring heat from your hand.

Procedure

  1. Place several small neodymium magnets (e.g., 1×1 cm) side by side to create a magnetic base.
  2. Gently place a thin piece of pyrolytic graphite on top of the magnets. Observe as it levitates slightly above them due to diamagnetism.
  3. Push the graphite lightly with a wooden stick. Notice that it resists being forced into the magnetic field, maintaining its hovering position.
  4. For the heat conduction demonstration, hold the piece of pyrolytic graphite in your hand and press it against an ice cube.
  5. Observe that the graphite cuts through the ice easily, as it rapidly conducts heat from your hand into the ice.
  6. Compare this with an iron sheet pressed against ice to see how much slower it melts.

Diamagnetic Levitation with Pyrolytic Graphite - $20 How-To - Kevin Patterson:


Levitate a Piece of Graphite on Magnets - $10 Project - Forrest Trenaman:


📄 Pyrolytic graphite - MEL Science: https://melscience.com/US-en/articles/pyrolytic-graphite/?srsltid=AfmBOooxjIRyp9DlevmnfBUOo2WYaT3bI0Q9U4PPwqvpfUJvaGbEBZhX

Variations

  • Arrange magnets in different orientations to see how the levitation stability changes.
  • Try different thicknesses of pyrolytic graphite to compare levitation height and stability.
  • Use a thermal camera to visualize heat transfer when the graphite melts ice.

Safety Precautions

  • Handle neodymium magnets carefully; they are strong and can pinch fingers or shatter if snapped together.
  • Keep magnets away from electronics, magnetic storage media, and medical implants.
  • Do not attempt to ingest or inhale graphite flakes.
  • Avoid dropping magnets on hard surfaces, as they can chip or break.
  • Wash hands after handling graphite.

Questions to Consider

  • Why does pyrolytic graphite levitate above magnets while most materials do not? (It is strongly diamagnetic, creating a repelling magnetic field.)
  • How does this compare to superconductors that also levitate? (Superconductors show perfect diamagnetism via the Meissner effect, while graphite shows weaker but noticeable diamagnetism.)
  • Why does graphite melt ice so quickly compared to iron? (It is an excellent thermal conductor, transferring heat from your hand efficiently into the ice.)
  • What practical applications exist for diamagnetic levitation? (Examples include magnetic levitation for frictionless bearings, stable positioning systems, and demonstrations of fundamental physics.)