We prepared multilayers, consisting of an epitaxial Au/Co/Au/Cus111d architecture on Sis111d substrates, to understand the magnetic anisotropy of an ultrathin Co layer in relation to its structure.
The room-temperature magnetization of an 8-monolayer sMLd-thick Co layer is predominately either in-plane or out-of-plane depending upon the thickness of the Au underlayer. Specifically, for
a Co film grown on a 2-ML-thick Au, the Co film has a distorted fcc structure and in-plane magnetic anisotropy. For a Co film grown on a 6-ML-thick Au, the Co film has a distorted hcp structure and
out-of-plane magnetic anisotropy.