An analysis of coercivity in various hard magnetic materials relating coercive field and activation volume

In usual analyses, the coercive field of hard magnetic materials is related to the main phase anisotropy. This may be questioned since coercivity is not an intrinsic material property. In a recent paper, we have shown that a relation may be established between two experimental parameters characterising coercivity, the coercive field and the activation volume. The temperature dependence of the coercive field in various hard magnets is discussed within this model. The coercivity mechanism which emerges from the analysis is passage or expansion. (C) 2002 Elsevier Science B.V. All rights reserved.