Abstract
The problem of depth dependence of the magnetization tilt angle θ(z) is solved analytically for an exchange-coupled ferromagnet with dipole energy, applied field, and surface anisotropy . For ≤(πA=, the surface magnetization direction remains in the plane, =θ(0)=π/2. For ≥, the magnetization vector moves out of the surface, initially with d/=-∞, then slowly approaches =0 as approaches infinity. For Fe, is of order 4 erg/. The results indicate that a perpendicular component of magnetization at the surface relaxes to its bulk in-plane orientation over a distance that is generally much shorter than the bulk domain-wall width. The surface remanence and initial susceptibility of the surface magnetization for in-plane applied field are calculated and provide useful expressions for interpreting experimental results. The experimentally measured surface magnetization increases linearly with probe sensitivity depth.
- Received 2 May 1990
DOI:https://doi.org/10.1103/PhysRevB.42.6568
©1990 American Physical Society