Analysis of ultra-narrow ferromagnetic domain walls

Abstract

A mathematical analysis of ultra-narrow ferromagnetic domain walls was undertaken, with graphical plots coded in the programming language TrueBASIC. An intrinsic inter-atomic potential stemming from the breakdown of the continuum approximation of matter is calculated and its contribution to the coercive force of hard materials is depicted. The interaction of a very narrow domain wall with a similarly narrow planar defect is analyzed. Time-dependent motion of such walls is modeled for various external driving forces and in different combinations of material parameters. This work was completed in parallel with a study of narrow crystallographic magnetic discontinuities known as twin boundaries, and was designed to gain an intuition into the control of high-anisotropy magnetic recording devices. The equations developed here would be particularly useful as a basis for approaching the calculations of the stability of high-density storage media.