Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/68521
Type: Artigo
Title: Growth study of Cu/Pd(111) by RHEED and XPS
Author: Siervo, A. de
Paniago, R.
Soares, E. A.
Pfannes, H.-D.
Landers, R.
Kleiman, G. G.
Abstract: An X-ray photoelectron spectroscopy (XPS) and reflection high-energy electron diffraction (RHEED) investigation of the growth of Cu films on a Pd(1 1 1) single crystal at room temperature is presented. Dynamically taken XPS-data as function of the deposition time show a linear variation of ICu-3p/IPd-3d and a periodic change of its slope indicating a nearly layer-by-layer growth process. RHEED oscillations are seen for the 3-4 first layers, also suggesting a smooth growth mode. From the evolution of the RHEED-streaks separation the in-plane Cu-atom spacing is precisely determined. Up to a coverage of ca. 2-3 monolayers (ML) Cu grows pseudomorphously on Pd(1 1 1), despite the -7.1% strain imposed by the substrate lattice parameter. Non-pseudomorphous epitaxial growth is evidenced above ca. 3-4 ML by a discontinuous change in lateral lattice spacing observed by RHEED which indicates a relaxation to the Cu(1 1 1) ''natural'' surface lattice parameter. In addition it is concluded that surface alloying does not take place at least at room temperature (RT)-XPS spectra taken dynamically during annealing show that alloying occurs only above RT.
An X-ray photoelectron spectroscopy (XPS) and reflection high-energy electron diffraction (RHEED) investigation of the growth of Cu films on a Pd(1 1 1) single crystal at room temperature is presented. Dynamically taken XPS-data as function of the deposition time show a linear variation of ICu-3p/IPd-3d and a periodic change of its slope indicating a nearly layer-by-layer growth process. RHEED oscillations are seen for the 3–4 first layers, also suggesting a smooth growth mode. From the evolution of the RHEED-streaks separation the in-plane Cu-atom spacing is precisely determined. Up to a coverage of ca. 2–3 monolayers (ML) Cu grows pseudomorphously on Pd(1 1 1), despite the -7.1% strain imposed by the substrate lattice parameter. Non-pseudomorphous epitaxial growth is evidenced above ca. 3–4 ML by a discontinuous change in lateral lattice spacing observed by RHEED which indicates a relaxation to the Cu(1 1 1) ‘‘natural’’ surface lattice parameter. In addition it is concluded that surface alloying does not take place at least at room temperature (RT)-XPS spectra taken dynamically during annealing show that alloying occurs only above RT.
Subject: Cobre
Paládio
Epitaxia por feixe molecular
Elétrons - Difração
Ligas (Metalurgia)
Espectroscopia fotoeletrônica de raio X
Country: Holanda
Editor: Elsevier
Citation: Surface Science. Elsevier Science Bv, v. 575, n. 41671, n. 217, n. 222, 2005.
Rights: fechado
Identifier DOI: 10.1016/j.susc.2004.11.028
Address: https://www.sciencedirect.com/science/article/pii/S003960280401492X
Date Issue: 2005
Appears in Collections:IFGW - Artigos e Outros Documentos

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