Uniaxial magnetic anisotropy tuned by nanoscale ripple formation: Ion-sculpting of Co/Cu(001) thin films

We have investigated the growth of surface nanostructures on a Co/Cu(001) film and the growth of Co films on a nanostructured Cu(001) substrate as well as the effect of nanoscale pattern formation on the film magnetic properties. Here we demonstrate by scanning tunneling microscopy measurements and magneto-optic Kerr effect hysteresis curves that low-temperature grazing-incidence ion sputtering can be used to induce the formation of nanoscale ripples which reduce the four-fold symmetry of the Cofilm to two-fold, thus generating a strong in-plane uniaxial magnetic anisotropy. The nanostructures and the associated uniaxial magnetic anisotropy were found to be stable up to room temperature.