MAGNETOOPTICAL ANISOMETRY OF ULTRATHIN COBALT FILMS

The advantage of magneto-optics to measure magnetic anisotropy constan ts in ultrathin films exhibiting perpendicular spin anisotropy is repo rted. This is illustrated for Au/Co/Au sandwiches with Co layer thickn ess ranging from 8 to 15 angstrom. We stress the importance of prelimi nary measurements always necessary to define the (H(parallel-to), H(pe rpendicular-to)) region in which a homogeneous spin rotation occurs. T hese results confirm the existence of interface anisotropy and lead to its estimation K(s) = 0.56 erg/cm2 whereas the volumic term is shown to be K(v) = 7.5 X 10(6) erg/cm3.