Co on h-BN/Ni(111):: from island to island-chain formation and Co intercalation

The growth of cobalt on a monolayer of hexagonal boron nitride on Ni(111) has been studied in a combination of scanning tunneling microscopy and X-ray photoelectron spectroscopy (XPS). A detailed picture of the growth kinetics is obtained. The Co sticking coefficient strongly decreases at high substrate temperatures. Co deposition results in two different morphologies: (i) three-dimensional clusters that grow on top of the hexagonal boron nitride (h-BN) film and often align themselves to form chains and (ii) islands with a more two-dimensional character, which are intercalated below the h-BN film dominate at higher substrate temperatures. From XPS measurements at different deposition temperatures an activation energy for intercalation of similar to0.24 eV is inferred. The influence of observed defect lines in the h-BN overlayer on the growth kinetics is discussed. (C) 2002 Elsevier Science B.V. All rights reserved.