Micromagnetic Study for Magnetic Properties of Exchange-Coupled Nanocomposite Magnetic Systems with α-Fe Grains Embedded in Nd ₂ Fe ₁₄ B Matrix

In this paper, the relationship between the magnetic properties and microstructures of nanocomposite isotropic exchange-coupled systems with the structure of α-Fe crystalline grains embedded in Nd ₂ Fe ₁₄ B matrices has been estimated by micromagnetic finite-element method. And then, the results have been analyzed by means of the effectiveness of exchange coupling between the magnetically hard Nd ₂ Fe ₁₄ B and soft α-Fe phase of the exchange-coupled Nd ₂ Fe ₁₄ B/α-Fe magnetic systems. The effectiveness of interphase exchange coupling has been estimated by the volume fractions of exchange coupling area near phase boundaries between α-Fe grains and Nd ₂ Fe ₁₄ B matrix. The results have shown the micromagnetic mechanism of the advanced magnetic properties of the exchange coupled magnetic systems with the structure of α-Fe grains embedded in Nd ₂ Fe ₁₄ B matrix. In addition, the optimal magnetic properties can be expected in the case of comparatively the large grain sizes of α-Fe and Nd ₂ Fe ₁₄ B phase due to the characteristic structure of those magnetic systems.