SPATIALLY RESOLVED MAGNETOOPTICAL INVESTIGATION OF THE PERPENDICULAR ANISOTROPY IN A WEDGE-SHAPED ULTRATHIN EPITAXIAL CO LAYER ON PD(111)

We have used the polar Kerr effect to measure the thickness dependence of the perpendicular anisotropy of ultrathin Co in Pd/Co/Pd(111) sandwiches in the 3-9 monolayer range. The anisotropy was determined from polar Kerr measurements of the perpendicular component of the magnetisation both as a function of the strength and the angle of the applied field. The Co layers were grown epitaxially in ultrahigh vacuum on a Pd(111) single crystal and covered by a 20 angstrom epitaxial Pd layer. The Co layer was deposited in the form of a wedge (0-9 monolayers) so that the thickness dependence of the anisotropy could be measured on a single sample.