13 research outputs found
Shadowing, focussing and charge-exchange effects in the angular distributions of keV Ne+ and H2O+ ions scattered from Cu{110}
No full textShadowing, focussing and charge exchange effects in the angular distributions of keV Ne and H2O ions scattered from Cu{110}
No full textReconstruction of the oxygen-covered Cu{110} surface identified with low energy Ne+ and H2O+ ion scattering
No full textOxygen adsorption on Cu(110): Determination of atom positions with low energy ion scattering
No full textThe influence of low energy ion beams on an adsorbing surface
No full textStrong enhancement of the oxygen-chemisorption at a Cu(110) surface is measured during low energy (some keV) noble gas (Ne+) ion bombardment. This phenomenon is independent of the coverage and is linearly related to the number of impinging ions per second. A model description of the oxygen adsorption on a Cu(110) surface is given: the model of dissociative adsorption via a mobile precursor state is extended to take into account the twofold symmetry of the surface. From a comparison of model calculations with the experimental results, model parameters can be estimated. The estimated parameters are in agreement with the adsorbate-structure deduced from LEED patterns. Ion-induced adsorption is discussed with the aid of this model
Investigation of oxygen adsorption on Cu(110) by low-energy ion bombardment
No full textThe interaction of molecular oxygen with a Cu(110) surface is investigated by means of low energy ion scattering (LEIS) and secondary ion emission. The position of chemisorbed oxygen relative to the matrix atoms of the Cu(110) surface could be determined using a shadow cone model, from measurements of Ne+ ions scattered by adsorbed oxygen atoms. The adsorbed oxygen atoms are situated 0.6 ± 0.1 Å below the midpoint between two adjacent atoms in a 100 surface row. The results of the measurements of the ion impact desorption of adsorbed oxygen suggest a dominating contribution of sputtering processes. Ion focussing effects also contributes to the oxygen desorption. The ion induced and the spontaneous oxygen adsorption processes are studied using different experimental methods. Sticking probability values obtained during ion bombardment show a strong increase due to the ion bombardment
Ion-induced adsorption of oxygen at a Cu(110) surface
No full textA preliminary report is given on experiments concerning the ion-induced adsorption of oxygen on copper. A strong enhancement of the sticking probability of oxygen is found during bombardment of the surface with neon ions in the keV region. The increase in the sticking probability is proportional to the primary ion intensities, used in this work (0.25–10 μA/ cm2)
