Evidence for a self-organized growth in granular Co/Al2O3 multilayers

By sequential deposition of thin layers of cobalt and alumina by sputtering , we have fabricated granular multilayers consisting of successive planes o f nanosized cobalt clusters separated by alumina along the growth direction . Combining grazing-incidence small-angle x-ray scattering and transmission electron microscopy experiments, we show that, in a given range of thickne ss, the vertical arrangement of clusters from plane to plane is not random but shows a topology-induced self-organization. (C) 2000 American Institute of Physics. [S0003-6951(00)01620-X].