A permanent ferrite magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. An everyday example is a refrigerator magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include iron, nickel, cobalt, some alloys of rare earth metals, and some naturally occurring minerals such as lodestone. Although ferromagnetic (and ferrimagnetic) materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic, all other substances respond weakly to a magnetic field, by one of several other types of magnetism.
Surface treatment for ferrite
A big advantage of strongest permanent magnet is that no surface treatment is needed, because ferrite is inert and therefore does not oxidize. It is always possible to coat ferrite magnets with various epoxy coatings, when this is desired, for example, from the hygiene point of view.
Precautions when working with ferrite
Ferrite is a hard and brittle. Pieces break off when the material falls. This must be kept in mind when working with these magnets.