Low-energy electron diffraction study of the growth of ultrathin films of face-centred cubic Co on Rh(001)

Publisher Website
Google Scholar
Abstract
The epitaxial growth of Co on Rh(001) at room temperature is studied by means of quantitative low-energy electron diffraction and Auger electron spectroscopy. The Co films are found to grow pseudomorphic to the substrate in the layer-by-layer mode for at least two layers. The interlayer spacing between the monolayer and the substrate is 1.77 +or- 0.03 AA. The first and second interlayer spacings for a bilayer film are 1.60 +or- 0.04 and 1.75 +or- 0.04 AA, respectively. Strained pseudomorphic films of up to 10 layers could be grown with a bulk lattice spacing of 1.60 +or- 0.03 AA and a 3.1%-expanded first interlayer spacing (1.65 +or- 0.03 AA. An elastic strain analysis shows that the equilibrium (unstrained) phase of these Co films is face-centred cubic: the bulk interlayer spacing is contracted by 9.7% with respect to the equilibrium value (1.772 AA) as a consequence of the large positive planar epitaxial strain produced by the 7.3% lattice mismatch between FCC Co and Rh.