Neodymium magnet

A permanent magnet made primarily from neodymium, iron, and boron. Its high magnetic strength comes from a crystalline structure that strongly resists changes in magnetization.

Nd₂Fe₁₄B: The tetragonal neodymium–iron–boron compound that forms the principal magnetic phase in neodymium magnets. Its crystal structure produces the strong magnetization and resistance to demagnetization that define the magnet.
Neodymium: A rare-earth chemical element with atomic number 60. Its unpaired electrons contribute strongly to the alloy’s magnetic behavior.
Brushless DC motor: An electric motor that uses electronic switching to control current through stationary windings. Neodymium magnets can provide strong rotor fields in compact motor designs.
Samarium–cobalt magnet: A permanent magnet made from samarium and cobalt, valued for high-temperature stability and corrosion resistance. It can withstand harsher heat and corrosion than neodymium magnets, though it is typically more costly.
Rare-earth element: One of 17 chemically similar elements comprising the 15 lanthanides, scandium, and yttrium. Neodymium is a rare-earth element whose supply affects magnet production.
Magnetocrystalline anisotropy: Dependence of a material’s magnetic properties on the direction of its crystal lattice. It makes magnetization much harder to reverse along the preferred axis of the magnet’s crystals.
Iron: A metallic chemical element with atomic number 26 and strong ferromagnetic properties. Iron supplies much of the alloy’s magnetic moment.
Hard disk drive: A data-storage device that records information magnetically on rotating disks. Small neodymium magnets have been used in its voice-coil actuator assemblies.
Alnico magnet: A permanent magnet alloy composed mainly of aluminum, nickel, cobalt, and iron. Alnico tolerates high temperatures but generally has lower coercivity than neodymium magnets.
Rare-earth mining: The extraction and processing of rare-earth elements from mineral deposits. Producing the neodymium used in magnets can create substantial waste and pollution.

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