Ferrite magnets

Ferrite (also called black) magnets are classic powder metallurgical magnets based on barium and strontium oxides.
Although they do not have particularly high magnetic characteristics, their low price has made them widely used in classic electric motors, generators, sensors, loudspeakers, advertising materials and souvenirs.
Due to their resistance to aggressive environments and their high specific electrical resistance (like that of ceramics), they are used in specialized sensors and devices.