Hard ferrite (ceramic) magnets were developed in the 1960's as a low cost alternative to metallic magnets. Even though they exhibit low energy and are relatively brittle and hard, ferrite magnets have won wide acceptance due to their good resistance to demagnetization, excellent corrosion resistance and low price per pound. In fact, measured by weight, ferrite represents more than 75 percent of the world magnet consumption. It is the first choice for most types of DC motors, magnetic separators, magnetic resonance imaging and automotive sensors.