Low cost, low price. Raw materials are cheap. 2. Good temperature stability. It can be used at -40°C and +350°C. 3. Just mentioned that there is no rust. 4. The demagnetization curve is approximately a straight line. 5. Lightweight, density (4.6-5.1) x103kg/m3 6. The anisotropy constants of magnetic crystals are large. 7. High coercivity HC (between Al Ni Co alloy and rare earth cobalt permanent magnet) 8. High resistivity.