References of "M., Urbassek Herbert"
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See detailSputtering at grazing ion incidence: Influence of adatom islands
Rosandi, Yudi; Redinger, Alex UL; Michely, Thomas et al

in PHYSICAL REVIEW B (2010), 82(12),

When energetic ions impinge at grazing incidence onto an atomically flat terrace, they will not sputter. However, when adatom islands (containing N atoms) are deposited on the surface, they induce ... [more ▼]

When energetic ions impinge at grazing incidence onto an atomically flat terrace, they will not sputter. However, when adatom islands (containing N atoms) are deposited on the surface, they induce sputtering. We investigate this effect for the specific case of 83 degrees-incident 5 keV Ar ions on a Pt (111) surface by means of molecular-dynamics simulation and experiment. We find that-for constant coverage Theta-the sputter yield has a maximum at island sizes of N congruent to 10-20. A detailed picture explaining the decline of the sputter yield toward larger and smaller island sizes is worked out. Our simulation results are compared with dedicated sputtering experiments, in which a coverage 0.09 of Pt adatoms are deposited onto the Pt (111) surface and form islands with a broad distribution around a most probable size of N congruent to 20. [less ▲]

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See detailInfluence of a single adatom on sputtering at grazing incidence - A molecular-dynamics case study of 5 keV Ar impact on Pt (111)
Rosandi, Yudi; Redinger, Alex UL; Michely, Thomas et al

in SURFACE SCIENCE (2009), 603(2), 320-325

Grazing incidence ion impact on a flat terrace lets the projectile reflect specularly off the surface, leading to little or no damage production or sputtering. The presence of isolated surface defects may ... [more ▼]

Grazing incidence ion impact on a flat terrace lets the projectile reflect specularly off the surface, leading to little or no damage production or sputtering. The presence of isolated surface defects may change this behaviour drastically. We investigate this phenomenon for the specific case of 5 keV Ar ions impinging at 83 degrees towards the surface normal onto the Pt (111) surface. Molecular-dynamics simulations allow to study the influence of isolated adatoms in detail. The scattering of the projectile from the adatom can redirect the projectile, or let the adatom recoil, such that either of them deposits considerable energy in the target surface, leading to abundant damage production and sputtering. Two distinct collision zones are identified: (i) When the projectile hits the surface in front of the adatom, it may collide with the adatom indirectly (after being specularly reflected off the surface); (ii) alternatively, it may hit the adatom directly. We quantify our results by measuring the zone of influence (congruent to 13 angstrom(2)) around the adatom, into which the projectile must hit in order to collide with the adatom, and by the sputter cross section of roughly 110 angstrom(2). The data compare well with previous simulation results of sputtering from an atomically rough surface. (C) 2008 Elsevier B.V. All rights reserved. [less ▲]

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See detailCompetition of terrace and step-edge sputtering under oblique-incidence ion impact on a stepped Pt(111) surface
Rosandi, Yudi; Redinger, Alex UL; Michely, Thomas et al

in NUCLEAR INSTRUMENTS METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS (2009), 267(16), 2769-2773

Using molecular-dynamics simulation, we study the sputtering of a Pt(111) surface under oblique and glancing incidence 5 keV Ar ions. For incidence angles larger than a critical angle theta(c), the ... [more ▼]

Using molecular-dynamics simulation, we study the sputtering of a Pt(111) surface under oblique and glancing incidence 5 keV Ar ions. For incidence angles larger than a critical angle theta(c), the projectile is reflected off the surface and the sputter yield is zero. We discuss the azimuth dependence of the critical angle theta(c) with the help of the surface corrugation felt by the impinging ion. If a step exists on the surface, sputtering occurs also for glancing incidence theta > theta(c). We demonstrate that for realistic step densities, the total sputtering of a stepped surface may be sizable even at glancing incidence. (C) 2009 Elsevier B.V. All rights reserved. [less ▲]

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