Ferrite Magnets or Ceramicsare sintered permanent magnets composed of barium or strontium carbonate, and iron oxide. This class of magnets, aside from good resistance to demagnetization, has the popular advantage of low cost. The sorts of hard ferrite magnets are manifold and complete. They are charcoal gray in color and usually appear in the forms of toroid, circular disk, square, bar, arc segment, blocks, rings, cylinders special magnets etc. The detail specifications are up to hundreds of kinds.