NdFeB
NdFeB (also known as neodymium magnet or Neo magnet) is the most widely used type of rare-earth magnet. It is a permanent magnet made from an alloy of neodymium, iron, and boron to form the Nd₂Fe₁₄B tetragonal crystalline structure.
Neodymium magnets can be found in a variety of applications including high performance motors, brushless DC motors, magnetic separation, magnetic resonance imaging, sensors, switches and loudspeakers.