The magnetic performance indicators of permanent magnet materials mainly include residual magnetism (Br), magnetic induced coercivity (bHc), intrinsic coercivity (jHc), and maximum magnetic energy product (BH) max. In addition, there are several other magnetic performance indicators: Curie temperature Tc, working temperature Tw, residual magnetic temperature coefficient α、 Temperature coefficient of intrinsic coercivity β、 Recovery permeability μ Rec. Demagnetization curve squareness Hk/jHc.