The structures of strained Cu films which had been deposited onto (00•1) Ru surfaces at 720K were investigated by using X-ray diffraction techniques. The results showed that a single Cu monolayer adopted a pseudomorphic structure, with the first 3 interlayer spacings being significantly relaxed. The 2-layer structure consisted of a commensurate uniaxially-modulated stripe-phase reconstruction. The prediction of the diffraction intensities, using simulated annealing techniques and least-squares refinement, led to a crystallographic description of the structure in terms of a set of 3-dimensional modulation functions. It was found that the reconstruction persisted through both Cu layers, and led to relaxation of the Cu and Ru interlayer spacings.

Structure of Pseudomorphic and Reconstructed Thin Cu Films on Ru(00•1). H.Zajonz, A.P.Baddorf, D.Gibbs, D.M.Zehner: Physical Review B, 2000, 62[15], 10436-44