Extended theory of the coercive force due to domain wall pinning

Abstract

We have enlarged the theory of ferromagnetic domain wall pinning by defects to include large as well as small deviations of the magnetic anisotropy, magnetization, and/or magnetic exchange energy of the defect, from the host material for all values of the defect width. In particular, we obtain results for the coercive force due to such pinning as a function of two dimensionless constants characterizing the defect and of the defect width. We also obtain results for the maximum obtainable coercive force in terms of these parameters. We discuss these results in terms of applications to the Sm2(Co, Cu, Zr, Fe)17 hard magnetic materials.