AVS 45th International Symposium
    Surface Science Division Wednesday Sessions
       Session SS3-WeM

Paper SS3-WeM8
Evolution and Structure of the Stripe Phase Reconstruction of Cu/Ru(0001)

Wednesday, November 4, 1998, 10:40 am, Room 314/315

Session: Surface Dynamics and Roughening
Presenter: H. Zajonz, Brookhaven National Laboratory
Authors: H. Zajonz, Brookhaven National Laboratory
D. Gibbs, Brookhaven National Laboratory
A.P. Baddorf, Oak Ridge National Laboratory
D.M. Zehner, Oak Ridge National Laboratory
Correspondent: Click to Email
X-ray scattering studies of the structure of Cu layers deposited on Ru(0001) substrates during growth and versus substrate temperature have been initiated. The nearest-neighbor spacing in bulk fcc Cu is 5.8% smaller than that in hcp Ru. Earlier STM studies,@footnote 1@ established that the first layer of Cu on Ru(0001) adopts a pseudomorphic structure, but that the two-layer film exhibits a stripe-phase reconstruction which consists of an uniaxial modulation of Cu chains along [100]. Measured x-ray intensities provide evidence that the first layer does not remain pseudomorphic in the stripe phase. Our experiments also involve characterizing the appearance and evolution of the stripe-phase reconstruction peak as a function of Cu coverage and substrate temperature. At 720 K, x-ray scattering confirms a pseudomorphic Cu structure for coverages up to about one monolayer, followed by the growth of a stripe-phase reconstruction between one and two layers. In the stripe phase, the average Cu spacing along the rows is that of Cu bulk, however between rows the spacing is equivalent to that of Ru. At two monolayers coverage, there is an abrupt contraction of the average Cu spacing by an additional ~0.5% which can be attributed to an increase in the amplitude of the transverse modulations with layer completion. This phenomenon has not been observed previously for an interfacial reconstruction. ORNL is managed by Lockheed Martin Energy Research Corp. under U.S. Department of Energy contract DE-AC05-96OR22464. Work at BNL is supported by DOE, under contract DE-AC02-98CH10886. @FootnoteText@ @footnote 1@ C. Günther et al., Phys. Rev. Lett. 74, 754 (1995)