Pg. Clark et Cm. Friend, Interface effects on the growth of cobalt nanostructures on molybdenum-based substrates, J CHEM PHYS, 111(15), 1999, pp. 6991-6996
Using scanning tunneling microscopy and low energy electron diffraction, we
show that the structure and morphology of cobalt islands deposited on clea
n, sulfur- and oxygen-covered Mo(110) at 400 K strongly depends on the natu
re of the interface. Two-dimensional islands of cobalt grow on clean and S-
covered Mo(110), whereas three-dimensional islands grow on O-covered Mo(110
). The islands on the clean surface are hexagonal, reflecting the structure
of the bulk Co lattice. A square lattice is formed on the S-covered surfac
e that is the result of significant S-Co interactions. The difference betwe
en the growth mode of the cobalt on sulfur- and oxygen-covered Mo(110) and
the difference in island shape on clean and S-covered Mo(110) are both expl
ained in terms of microscopic bonding differences at the interface related
to the degree of charge transfer to the O and S from the Mo surface. (C) 19
99 American Institute of Physics. [S0021-9606(99)70739-7].