References of "Urbassek, Herbert M"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailTrails of Kilovolt Ions Created by Subsurface Channeling
Redinger, Alex UL; Standop, Sebastian; Michely, Thomas et al

in PHYSICAL REVIEW LETTERS (2010), 104(7),

Using scanning tunneling microscopy, we observe the damage trails produced by keV noble-gas ions incident at glancing angles onto Pt(111). Surface vacancies and adatoms aligned along the ion trajectory ... [more ▼]

Using scanning tunneling microscopy, we observe the damage trails produced by keV noble-gas ions incident at glancing angles onto Pt(111). Surface vacancies and adatoms aligned along the ion trajectory constitute the ion trails. Atomistic simulations reveal that these straight trails are produced by nuclear (elastic) collisions with surface layer atoms during subsurface channeling of the projectiles. In a small energy window around 5 keV, Xe(+) ions create vacancy grooves that mark the ion trajectory with atomic precision. The asymmetry of the adatom production on the two sides of the projectile path is traced back to the asymmetry of the ion's subsurface channel. [less ▲]

Detailed reference viewed: 71 (2 UL)
Full Text
Peer Reviewed
See detailStep-edge sputtering through grazing incidence ions investigated by scanning tunneling microscopy and molecular dynamics simulations
Redinger, Alex UL; Rosandi, Yudi; Urbassek, Herbert M. et al

in PHYSICAL REVIEW B (2008), 77(19),

Scanning tunneling microscopy is used to quantify step-edge sputtering of Pt(111) at 550 K by grazing incidence ion bombardment with 5 keV Ar(+) ions. For bombardment conditions causing negligible erosion ... [more ▼]

Scanning tunneling microscopy is used to quantify step-edge sputtering of Pt(111) at 550 K by grazing incidence ion bombardment with 5 keV Ar(+) ions. For bombardment conditions causing negligible erosion on terraces, damage features associated with step bombardment allow us to visualize step retraction and thus to quantify the step-edge sputtering yield. An alternative method for step-edge yield determination, which is applicable under more general conditions, is the analysis of the concentration of ascending steps together with the removed amount as a function of ion fluence. Interestingly, the azimuthal direction of the impinging ions with respect to the surface significantly changes the sputtering yield at step edges. This change is attributed to the orientation dependence of subsurface channeling. Atomistic insight into step-edge sputtering and its azimuthal dependence is given by molecular dynamics simulations of ion impacts at 0 and 550 K. The simulations also demonstrate a strong dependence of the step-edge sputtering yield on temperature. [less ▲]

Detailed reference viewed: 77 (3 UL)
Full Text
Peer Reviewed
See detailMechanisms of pattern formation in grazing-incidence ion bombardment of Pt(111)
Hansen, Henri; Redinger, Alex UL; Messlinger, Sebastian et al

in PHYSICAL REVIEW B (2006), 73(23),

Ripple patterns forming on Pt(111) due to 5 keV Ar(+) grazing-incidence ion bombardment were investigated by scanning tunneling microscopy in a broad temperature range from 100 to 720 K and for ion ... [more ▼]

Ripple patterns forming on Pt(111) due to 5 keV Ar(+) grazing-incidence ion bombardment were investigated by scanning tunneling microscopy in a broad temperature range from 100 to 720 K and for ion fluences up to 3x10(20) ions/m(2). A detailed morphological analysis together with molecular dynamics simulations of single ion impacts allow us to develop atomic scale models for the formation of these patterns. The large difference in step edge versus terrace damage is shown to be crucial for ripple formation under grazing incidence. The importance of distinct diffusion processes-step adatom generation at kinks and adatom lattice gas formation-for temperature dependent transitions in the surface morphology is highlighted. Surprisingly, ion bombardment effects like thermal spike induced adatom production and planar subsurface channeling are important for pattern ordering. [less ▲]

Detailed reference viewed: 64 (4 UL)