Hard ferrite magnets are made from iron oxide and barium carbonate or strontium carbonate. According to a recipe, the individual raw materials are mixed, granulated and calcinated (pre-sintered). Via different intermediate phases, a hexagonal ferrite phase (BaFe₁₂O₁₉ or SrFe₁₂O₁₉) is created. The pre-sintered granulate is ground further and can be pressed or sintered in the magnetic field – either wet or dry (anisotropic) or without magnetic field (isotropic). As ceramic materials, hard-ferrites have the proper mechanical properties with regard to hardness and brittleness. They can be machined, e.g. by grinding via diamond discs.

Rare earth magnets mainly consist of intermetallic compounds of rare earth metals (samarium, neodymium) and transition metals (e.g. cobalt, iron). In contrast to hard ferrite magnets, the grinding, pressing and sintering take place in an inert gas atmosphere. The magnets are either pressed in an oil bath (isostatic) or in a tool (axially or diametrical). They can then be further machined, e.g. by grinding at diamond discs.

Samarium-cobalt (SmCo) and neodymium-iron-boron (NdFeB) are important base alloys for rare earth magnets. The microstructure of sintered NdFeB materials is characterised by Nd2Fe14B grains as the magnetic main phase and the intermetallic grain boundary area. In the case of conventional NdFeB materials, the grain boundary area consists of free neodymium prone to corrosion. In the case of our NdFeB materials, this free neodymium is replaced by a stable intermetallic phase if possible, as well as corrosion-stabilised. This significantly decreases the susceptibility to corrosion of the materials. Principally, NdFeB is relatively stable to solvents and has a strong corrosive reaction to salts and acids. Hydrogen makes the material brittle. The corrosion-stabilising NdFEB magnets can be used unprotected for many applications.