Relaxation processes and coercivity in hard magnets

We discuss, in terms of 1D and 2D micromagnetic models, the basic characteristics of the demagnetization mechanisms acting in hard magnetic materials. This includes the study of the hysteretic and relaxational processes and, particularly, the investigation of the temperature dependence of coercivity. From our results we conclude that, even in highly anisotropic materials, demagnetization should be described in terms of nucleation and propagation of finite magnetic moment structures of the domain wall type.