Microstructure improvement related coercivity enhancement for sintered NdFeB magnets after optimized additional heat treatment

The distribution of the stray field corresponding to the beginning of the reversal process under the applied field approaches zero calculated from the surface in the model, which shows that the largest stray field exists at the intergranular phase. The presence of these non-ferromagnetic phases is expected to produce the magnetic stray field opposite to the spontaneous magnetization in the neighboring grains, thereby reduce the ideal nucleation field.312