Rare Earth magnets, the world’s strongest, are synthesized by alloying certain rare Earth elements with other materials.
Data from First4Magnets are used to compare the strength of these magnets. The maximum energy product, measured in mega-gauss-oersteds (MGOe), is one of the primary indicators of magnetic strength. It is a multiplication of a magnet’s remanence and its coercivity.
To become magnets, ferromagnetic substances need to enter the magnetic field of an existing magnet. Remanence, measured in Gauss, is the magnetism left in the magnet after removing the external magnetic field. Coercivity is the energy required to bring a magnetic material’s magnetism down to zero. Measured in oersteds, it essentially captures the magnetic material’s resistance to demagnetization.
Neodymium and samarium — two of the 17 rare Earth elements — are ferromagnetic, meaning that they have inherent magnetic properties and can be magnetized. Neodymium magnets are typically composed of one-third neodymium, along with iron and boron. Due to their strength, neodymium magnets are increasingly deployed in mobile phones, laptops and electric vehicle motors. Their relatively high strength for a smaller size also renders these magnets suitable for wind turbine.
Samarium-cobalt magnets exhibit exceptional resistance to extreme temperatures. These magnets can operate from temperatures as low as -270° C up to 350° C and are also highly resistant to corrosion. Consequently, they have important applications in harsh marine environments and technologies with high operating temperatures.
[Discover more about rare Earth magnet technology and manufacturers on GlobalSpec.com]
