parameters to describe permanent magnet materials:

• remanence  B_r  [T]
• coercive force of polarisation  H_cJ  [kA/m]
• coercive force of induction  H_cB  [kA/m]
• energy product  (BH)_max  [kJ/m³]

for characterisation of permanent magnet materials the demagnetisation curve (second quadrant of hysteresis loop) is of importance

the magnetic quality of a permanent magnet is given by the energy product  (BH)_max

with the remanence B_r , the theoretical (BH)_max

is given by

this value is reached when H_cB is maximum