Precision analysis of magnetization process in Nd2Fe14B sintered magnets

In a previous study, the authors studied the magnetization and demagnetization of Sm₁₂Fe₁₇N₃ magnet particles, and found three categories of particles; (1) multi-domain particles (MDP), (2) single-domain particles (SDP) and (3) saturable multi-domain particles (SMDP) that can be magnetized under a certain applied field and behave as SDP after. In this paper, the authors explored this categorization to the Nd₂Fe₁₄B sintered magnets in which the strong interactions are expected among the crystal grains. The behavior of SMDP in the sintered magnets, and the origin of enhancement of coercivity with the optimization of annealing temperature are studied using the method of analysis applied to the Sm₂Fe₁₇N₃ magnet particles.