Preferential ejection of bombardment sputtered and reflected atoms in the keV of Cu(110) with noble gas ions

Citation
Tt. Nuver et al., Preferential ejection of bombardment sputtered and reflected atoms in the keV of Cu(110) with noble gas ions, NUCL INST B, 179(4), 2001, pp. 503-514
Citations number
44
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences","Instrumentation & Measurement
Journal title
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
ISSN journal
0168-583X → ACNP
Volume
179
Issue
4
Year of publication
2001
Pages
503 - 514
Database
ISI
SICI code
0168-583X(200109)179:4<503:PEOBSA>2.0.ZU;2-1
Abstract
We have studied the preferential ejection of sputtered and reflected atoms during the bombardment of Cu(110) with keV noble gas ions (Xe, Kr, Ar) usin g the MARLOWE code. We have considered the sputtering both at low and high ejection energies. Our calculations lead us to the following interpretation of the spot formation in the angular distributions of the sputtered atoms: the Cu atoms escape from the crystal through the open directions in the cr ystal surface, i.e. those directions in which the outgoing atoms are not bl ocked by their neighbours when they travel from their initial position towa rds the vacuum. The atoms surrounding these directions act Eke atomic lense s. The individual spots are formed by ejecting atoms of one of the first fo ur surface layers, and the positions of the spots roughly coincide with the open directions. Our results strongly suggest that focusing collision sequ ences do not contribute significantly to the preferential ejection observed in our simulations. For the Ar-bombardment we have shown that the high-ene rgy reflected noble gas ions use the same open directions to escape from th e crystal. After reaching their deepest point inside the crystal, the Ar io ns suffer from additional collisions with target atoms before leaving the c rystal via one of the open directions. (C) 2001 Elsevier Science B.V. All r ights reserved.