Magnetic easy axis engineering in ultrathin Cu/Co/Cu(110)

The switching of the magnetic easy axis by exposing ultrathin Co/Cu(110) fi lms to CO gas and the subsequent reversing of this effect upon the depositi on of submonolayers of Cu has been investigated, using in situ magneto-opti c Kerr effect. The easy axis switching is attributed to the competition bet ween the cubic anisotropy K-1, and the effective uniaxial anisotropy K-u(ef f) which have different symmetry axes. For Co films > 15 ML, K-1, is compar able to K-u(eff) and the competition between the anisotropies as Cu is depo sited, allows us to controllably engineer the magnetization direction at a constant Co thickness. (C) 1999 Elsevier Science B.V. All rights reserved.