Bar magnet 40mm x 20mm x 10mm

Permanent ferrite magnets are made of hard ferrites , which have high coercivity and high remanence after magnetization. Iron oxide and barium or strontium carbonate are used to make hard ferrite magnets. High coercivity means that materials are very resistant to magnetization, which is the basic characteristic of a permanent magnet . They also have high magnetic permeability. These so - called ceramic magnets are cheap and widely used in household products such as fridge magnets . The maximum magnetic field B is about 0.35 tesla, and the magnetic field strength H is about 30–160 kiloampere-turns/meter (400–2000 oersted). The thickness of ferrite magnets is about 5 g/cm3.