Domain Walls in Ferromagnetic Dy and Tb

Abstract

The spin structure and energy of ferromagnetic domain walls in Dy and Tb have been calculated, using an iterative method which takes into account exchange interactions, magnetocrystalline anisotropy, and magnetoelastic anisotropy. The domain walls are found to be very thin (less than 20 atom layers) and to have relatively high energy (∼10 erg/cm2), as compared to the ferromagnetic transition metals. An intrinsic coercive force for wall motion is predicted for these very thin walls; it is analogous to the Peierls-Nabarro force on a dislocation, and is estimated to be of the order of 1 kOe for Dy and 30 Oe for Tb at absolute zero.