Initial sticking probability of O2 on Cu(410)

Vattuone, L.; Savio, Letizia; Okada, Michio; Moritani, Kousuke; Rocca, M.

doi:10.1016/j.susc.2008.06.031

Cited by 5 publications

(3 citation statements)

References 27 publications

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“…This oxygen phase was obtained with an O 2 exposure of 1.8 ML at 150 K. The corresponding spectrum is reported in figure 1(b): the broad energy loss peaked at ∼42 meV indicates dissociative O 2 adsorption with the formation of a disordered oxygen adlayer in which adatoms occupy both the fourfold hollows of the (100) terraces [36,37] and bridge sites at the step [17,39]. When dosing O 2 at normal incidence at a translational energy of 90 meV the initial sticking probability is ∼0.2 and depends little on the angle of incidence [47]. Due to the rapid decrease of sticking probability with coverage and temperature, we can estimate that, after an exposure of 1.8 ML by backfilling, the O coverage should not exceed 0.1 ML.…”

Section: Methodsmentioning

confidence: 99%

Poisoning and non-poisoning oxygen on Cu(410)

Vattuone

Venugopal

Kravchuk

et al. 2011

J. Phys.: Condens. Matter

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We have investigated ethene and oxygen co-adsorption on Cu(410) by high resolution electron energy loss spectroscopy. We find that these two species compete for the adsorption sites and that pre-exposure to oxygen affects ethene adsorption more or less strongly depending on oxygen coverage and the kind of occupied sites. The c(2 × 2) O overlayer is inert with respect to ethene adsorption, while when some oxygen is removed by thermally induced subsurface incorporation, ethene chemisorption is restored. The latter species also adsorbs on the disordered oxygen phase formed when O(2) is dosed at low crystal temperature. Contrary to the bare surface case, most of the ethene ends up in a π-bonded configuration. Dehydrogenation occurs, too, albeit as a minority channel. The so-produced carbon reacts already at low temperature with adsorbed oxygen to yield carbon monoxide, which desorbs around 190 K.

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Section: Methodsmentioning

confidence: 99%

Poisoning and non-poisoning oxygen on Cu(410)

Vattuone

Venugopal

Kravchuk

et al. 2011

J. Phys.: Condens. Matter

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“…Oxygen adsorption on Cu(410) has been studied extensively. 24,[28][29][30][31][32][33][34][35][36][37] The Cu(410) surface is particularly stable when exposed to oxygen and several surfaces vicinal to Cu(100) to (410) in the presence of adsorbed oxygen. 38,39 The early study by Thompson and Fadley 24 showed that the clean Cu(410) surface does not reconstruct.…”

Section: Oxygen On Ag(211)mentioning

confidence: 99%

Oxygen and sulfur adsorption on vicinal surfaces of copper and silver: Preferred adsorption sites

Liu

Thiel

2018

The Journal of Chemical Physics

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We present an extensive density functional theory (DFT) study of adsorption site energetics for oxygen and sulfur adsorbed on two vicinal surfaces of Cu and Ag, with the goal of identifying the most stable adsorption site(s), identifying trends and common themes, and comparing with experimental work in the literature where possible. We also present benchmark calculations for adsorption on the flat (111) and (100) surfaces. The first vicinal surface is the (211), and results are similar for both metals. We find that the step-doubling reconstruction is favored with both adsorbates and is driven by the creation of a special stable fourfold hollow (4fh) site at the reconstructed step. Zig-zag chain structures consisting of X-M-X units (X = chalcogen, M = metal) at the step edge are considered, in which the special 4fh site is partially occupied. The zig-zag configuration is energetically competitive for oxygen but not sulfur. DFT results for oxygen agree with experiment in terms of the stability of the reconstruction, but contradict the original site assignment. The second vicinal surface is the (410), where again results are similar for both metals. For oxygen, DFT predicts that step sites are filled preferentially even at lowest coverage, followed by terrace sites, consistent with the experiment. For sulfur, in contrast, DFT predicts that terrace sites fill first. Oxygen forms O-M-O rows on the top edge of the step, where it occupies incomplete 4fh sites. This resolves an experimental ambiguity in the site assignment. For both the (211) and (410) surfaces, the interaction energy that stabilizes the X-M-X chain or row correlates with the linearity of the X-M-X unit, which may explain key differences between oxygen and sulfur.

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“…In our previous work, carried out at normal incidence using pure classical dynamics, we also showed that, due to the nature of the chemisorption wells, the inclusion of the surface degrees of freedom (DOFs) was essential to reproduce qualitatively King and Wells sticking experimental measurements; 31 contrary to results obtained for other O 2 /metal systems, where the effect of the surface DOFs was found to be relatively small 21 or even negligible. 39 In our previous studies, 35,36 we also simulated the sticking (molecular + dissociative adsorption) probabilities for one and two layers of Cu grown on Ru(0001). For these two systems, our simulations also reproduced qualitatively the experimental measurements at super-thermal energies.…”

Section: Introductionmentioning

confidence: 99%