As a rare earth permanent magnetic material, Nd-Fe-B has high magnetic energy product, coercive force and high energy density with good mechanical property, and it is the strongest permanent magnet in the world, so it has been the widely used in modern industry and electronic technology.
Ferrite magnets are made of hard ferrites, which have a high coercivity and high remanence after magnetization. Iron oxide and barium or strontium carbonate are used in manufacturing of hard ferrite magnets.The high coercivity means the materials are very resistant to becoming demagnetized, an essential characteristic for a permanent magnet.
Before the development of rare earth magnets, alnico magnets ruled the magnet world.
While they are overshadowed and have largely been replaced by stronger rare earth magnets, alnico magnets are still commonly used in various industries for specific jobs such as high temperature handling equipment and manufacturing of sensors, to name a few.