Magneto-optical anisometry of ultrathin cobalt films

The advantage of magneto-optics to measure magnetic anisotropy constants in ultrathin films exhibiting perpendicular spin anisotropy is reported. This is illustrated for Au/Co/Au sandwiches with Co layer thickness ranging from 8 to 15 Å. We stress the importance of preliminary measurements always necessary to define the (H∥,H⊥) region in which a homogeneous spin rotation occurs. These results confirm the existence of interface anisotropy and lead to its estimation Ks=0.56 erg/cm2 whereas the volumic term is shown to be Kv=7.5×106 erg/cm3.