ORIENTATION DEPENDENCE OF THE POLAR KERR-EFFECT IN FCC AND HCP CO

Anisotropy of the energy dependent polar magneto-optical Kerr effect a s a function of the angle between the magnetization and crystallograph ic axes is reported. These results are obtained on epitaxially oriente d optically opaque films of hcp Co grown in two different crystallogra phic orientations by molecular beam epitaxy. Respective Kerr spectra o f fcc Co films are found to be insensitive to the magnetization direct ion. This Kerr anisotropy is correlated with the presence of strong ma gnetocrystalline anisotropy in the hcp phase of Co. A perturbation the ory treatment of the spin orbit coupling correctly predicts the order of magnitude of this new effect.