Diamagnetic Levitation
Purpose
Students observe small permanent magnets levitated by strongly diamagnetic materials (pyrolytic carbon and bismuth), demonstrating that magnetic repulsion exists and that not all magnetic interactions are attractive. Two apparatus versions are available: a self-contained jar for small classes and a bismuth platform requiring video projection for larger rooms.
Figure 1:
Close-up of the two bismuth crystal pieces used for the levitation demo. The iridescent colors are from surface oxidation.
Figure 2:
Bismuth levitation kit: two bismuth pieces on the wooden base. The external ceramic magnets and small levitating magnet are not visible in this view.
Figure 3:
Pyrolytic carbon levitation jar. Two carbon slabs are fixed about half a centimeter apart, with a small magnet between them. Ceramic magnets in an adjustable mount at the top provide the external field. Self-contained and suitable for passing around a small classroom.