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Pd on Cu(110): growth mode monitored by LEIS
Author(s) -
Delichère P.,
Bertolini J. C.
Publication year - 2002
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.1265
Subject(s) - palladium , copper , x ray photoelectron spectroscopy , metal , chemistry , analytical chemistry (journal) , low energy ion scattering , crystallite , monolayer , diffusion , ion , crystallography , catalysis , chemical engineering , thermodynamics , biochemistry , physics , organic chemistry , chromatography , engineering
Metal on metal deposits can have very different, and interesting, physical and chemical properties compared with those of the pure metal. In this framework we investigated the behaviour of low amounts of palladium deposited at 300 K on the (110) face of copper, but copper is known to have a lower surface energy than palladium and therefore will tend to segregate at the surface, a process that depends on the temperature. The absolute calibration of the Pd deposit was made on a polycrystalline Cu sample with the combined use of XPS and Rutherford backscattering spectroscopy: for 6 × 10 15 Pd atoms cm −2 , the intensity ratio of Pd 3d5/2 /Cu 3s is 7.2. For Pd deposited at room temperature on Cu(110), the presence of a large amount of copper at the surface is clearly evidenced by low‐energy ion scattering. The Pd atomic concentration at the surface does not exceed 15% for one monolayer (ML) of Pd deposited (1 ML = 1.1 × 10 15 Pd atoms cm −2 ). This indicates either that Pd does not spray uniformly at the surface or that Cu diffusion and alloying effects do exist. These results are discussed in relation with some catalytic properties of the Pd on Cu(110) adlayers. Copyright © 2002 John Wiley & Sons, Ltd.