5.2.4 Magnetic surface anisotropies

This chapter describes magnetic surface anisotropy in single crystal surfaces. Magnetic surface anisotropy is the magnetic contribution to surface energy σ, which depends on the orientation of M_s in the surface. Using standard polar coordinates, with a polar angle θ between M_s, and the surface normal and an azimuth φ with respect to the direction of highest symmetry in the plane, σ is given. Out-of-plane and in-plane anisotropies may be given by the anisotropy constants K_s and K_s,p, respectively, or alternatively by anisotropy fields. K_s, and K_s,p can be determined (a) from film anisotropies; plotted vs. (1/film-thickness); film anisotropies can be determined from FMR, BLS or TOM; (b) from FMR lineshape and surface modes in FMR for bulk crystals; (c) from spin-wave resonances in thin films. Magnetic surface anisotropies of clean single crystal surfaces like Ni(100), Fe(100), and Fe(110) are tabulated.