Ferrite magnet – sintered
Hard ferrites are performed as barium ferrite (BaFe) and strontium ferrite (SrFe). Hard ferrites are low-cost magnets with good magnetic properties.
Hard ferrite has a similar hardness and brittleness to ceramic materials, so it is workable only with a diamond tool. As is typical of oxide ceramics, hard ferrite magnets display relatively resistant behavior towards moisture, solvents, alkaline solutions, weak acids, salts, lubricants and gas pollutants.
The remanence of hard ferrite magnets is about 0.20 to 0.40 Tesla, which is a factor of 10 smaller than that of NdFeB magnets. The coercive field strengths of approx. 200 kA/m are also only the 10th part of an NdFeB magnet.