Computer simulation of magnetic properties of anisotropic nanocomposite magnets

Magnetic properties of anisotropic nanocomposite magnets, composed of Nd₂Fe₁₄B and α-Fe grains, were analyzed by computer simulation using the micromagnetic theory. All of the remanence, the coercivity, and the maximum energy product increased with increasing the alignment of Nd₂Fe₁₄B grains. In particular, the increase in coercivity was enhanced by the loss of the averaging effect of magnetic anisotropy. The maximum energy product for a fully aligned magnet versus amount of α-Fe showed a peak at 50% α-Fe, and the maximum energy product of approximately 690 kJ/m³ was obtained. This value is much larger than the theoretical limitation for the single-phase Nd₂Fe₁₄B magnet but smaller than that calculated for a nanocomposite magnet with the Sm₂Fe₁₇N_x /α-Fe layer structure