Neodymium Magnets are the strongest of all permanent magnets available today. Neodymium Magnets are widely used today in hard disk drives, motors and cordless equipment. Neodymium Magnets are made from an alloy of Neodymium, Iron and Boron. Neodymium is one of the Rare earth elements in the Periodic Table.
Neodymium magnets have a high co-ercivity which means that it is difficult to demagnetize them. They also have high magnetic field strength. This makes them preferable over other magnets. Neodymium magnets are widely used in medical equipment.
However, Neodymium Magnets have a lower Curie Temperature around 80 deg. C, which is the temperature at which a magnet loses its magnetism or a ferromagnetic material becomes paramagnetic.
Neodymium magnets are brittle and can shatter easily. They can interfere with cardiac pacemakers.
Their high strength can cause bodily injury as they can attract materials like nails, iron balls through the human body. When these magnets are broken, they shatter into dust which is combustible.
They should not be brought near other magnets as they can be attracted with such a force that they shatter on impact. Fingers caught between two neodymium magnets can get crushed. These magnets should be kept out of the reach of children. Children who accidentally swallow these magnets can be seriously injured or even killed.
Neodymium magnets are extremely corrosive and can get easily oxidised when exposed to air. Hence, they are usually coated with a protective layer of zinc, epoxy or tin.