What is the second strongest magnet?

The second strongest magnet known is a type of neodymium magnet, specifically the NdFeB (neodymium-iron-boron) magnets, which have a maximum energy product (BHmax) of up to around 52 MGOe. These magnets are widely used in various applications, from electric motors to magnetic resonance imaging (MRI) machines. The strongest permanent magnet, however, is typically a specialized type of samarium-cobalt magnet, which surpasses neodymium magnets in terms of temperature stability and corrosion resistance.