One of the bismuth’s most interesting properties is that it is the most diamagnetic of all the elements. Diamagnetism is a property that means a substance is “anti-magnetic.
When diamagnetic bismuth is exposed to an external magnetic field. It creates its own magnetic field that opposes it and lightly repels it. For an element or compound to be diamagnetic, it must have no unpaired electrons.
Bismuth is the most diamagnetic pure element, but there are a few things that can be made to be more diamagnetic than bismuth. This includes superconductors and compounds such as pyrolytic graphite.
Diamagnetism is a key factor in current research into magnetic levitation. Magnetic levitation is an advanced technology, a method of suspending objects in place with no support other than magnetic fields.
Repelling Magnets
When magnets are held close together with opposite poles facing each other, they will repel each other quite strongly.
Unless the magnets are constrained though, one magnet will usually drift to the side and flip itself to become attracted to the other magnet.
Using a diamagnetic substance, such as bismuth, the stability of the system can be greatly increased.
A common way to demonstrate magnetic levitation is to put a small magnet between 2 pieces of bismuth. With a larger magnet above to offset the weight of the small magnet.
If all pieces of this setup are adjusted to be the correct distance apart. The small magnet can be made to levitate between the bismuth pieces.
Being lifted by the large magnet, but repelled on the top and bottom by the diamagnetic bismuth. The magnet will stay in the center of the bismuth pieces and will spin on its axis while floating.
Practical uses of magnetic levitation technology include maglev trains, cooling fans and wind turbines, and industrial equipment such as pumps, motors, and compressors.
NASA has also experimented with using maglev tracks to send rockets into space, launching them as far as they can with magnets before igniting the rockets to save on fuel.
Components In Magnetic Levitation
Most of these applications rely on the fact that the components in a magnetic levitation system do not touch, and therefore are not susceptible to wear and friction.
This increases efficiency, reduces maintenance costs, and increases the life of the system.
These applications of magnetic levitation technology show that bismuth will play an important part in research that is developing our future.
