Micromagnetic analysis of precipitation hardened permanent magnets

In multiphase Sm(Co,Fe,Cu,Zr)7.6alloys the relations between the microstructure and magnetization processes have been analysed after different annealing treatments by investigations of the domain structure and of the characteristic properties of the hysteresis loop. It is shown that large coercive fields may be attributed to concentration gradients of Cu in the phase boundary between the 5:1 and the 17:2 phases.