Ferrite magnets are made of ferromagnetic oxide materials. It is a hard magnetic material with high stability and low cost. Although its maximum energy product (BH)max is small, which results in lower permeability and magnetic field strength, it still has a high cost performance in some applications due to its low cost of materials. It is widely used in low frequency and medium frequency transformers, magnetic field shielding and magnetic levitation.
The structure of ferrite magnets belongs to acicular oxides, mainly composed of Fe2O3 and Fe3O4. Due to its stable chemical composition and mature processing technology, it has the advantages of high quality stability and low cost. However, due to the properties of its hard magnetic material, its mechanical strength is not high, and it needs to be coated to improve its practical performance.
The main parameters of ferrite magnets are: remanence Br and coercive force Hc. Br represents the magnetization ability of the material, and Hc indicates the magnetization durability of the material. In general, the higher the Br value, the greater the adsorption force of the magnet; the higher the Hc value, the more difficult it is to eliminate the magnetization of the magnet, and the better the retention of magnetism. Common ferrite magnets on the current market have Br between 4000-5000Gs and Hc between 2500-4500Oe.
Ferrite magnets have low cost performance, but due to their poor magnetic properties, they are mainly used in some areas where the magnetic requirements are not high, such as toys, magnetic contacts, etc. For areas requiring higher magnetic properties, neodymium iron boron magnets are a more ideal choice. However, in the long run, with the improvement of manufacturing process and the reduction of cost, the application of ferrite magnets in a wider range is not impossible.
