On the Role of Intergranular Exchange Coupling in the Magnetization Process of Permanent-Magnet Materials

Abstract

The existence of domain wall-like moment distributions associated to the interfaces between exchange-coupled grains of hard magnetic phases with different directions of the local easy axis is demonstrated in the framework of the micromagnetic approximation. These structures constitute a very effective seed for the development of magnetization reversal under applied fields significantly lower than the anisotropy field, as is evidenced through the discrete calculation of the equilibrium distributions of the interfacial moments under the action of applied demagnetizing fields.