Coercivity of hard magnetic material with soft imperfection was studied via micromagnetic simulations established on one-dimensional scheme. A transition region of anisotropy energy between soft and hard phases was involved by considering a power function of Formula: see text with Formula: see text varied from 0.5 to 3.0. Unlike the sharp-interface connection where a lower bound of coercivity exists, the presence of Formula: see text transition led the coercivity reduction unbounded. The quadratic case (Formula: see text) showed the steepest drop of coercivity when transition region is considerably thick, following a simple inverse law as Formula: see text with Formula: see text the coercivity normalized by anisotropy field and Formula: see text the transition thickness normalized by Bloch length. The magnetic reversals and the behaviours of thermal agitation were explored for various Formula: see text cases, and correlated to the energy profiles investigated by calculation of minimum energy paths.
He et al. (Fri,) studied this question.