Coercive field of a polycrystalline ferrimagnet with uni-axial anisotropy

Unlike the coercive field HcHc of a bulk ferrimagnet, which diverges at the compensation temperature TcompTcomp, the coercive field of a polycrystalline ferrimagnet with uni-axial anisotropy is shown to have a minimum at TcompTcomp. Despite this behavior, the field required for domain-wall motion still diverges at the compensation temperature. These ideas are used to treat a ferrimagnetic class of molecule-based magnets, the bimetallic oxalates, that exhibit a minimum coercivity at TcompTcomp.