Energy loss of light ions scattered off Al(110) single crystal surfaces at low energy (original) (raw)
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Energy losses of H and F ions in grazing scattering on a missing row reconstructed Au(110) surface
Physica Scripta, 2011
A joint experimental and theoretical study of low-keV H and F ions in grazing scattering on a missing row reconstructed Au(110) surface is presented. We show the influence of surface electronic corrugation and trajectory effects on energy-loss spectra. Measurements of energy losses for grazing angles scattering in surface channeling conditions for various azimuthal orientations of the crystal have been performed and discussed in semi-classical simulations, which allow us to delineate various trajectory classes that correspond to different contributions in the energy-loss spectra for various azimuthal orientations of the surface.
Target effects in the interaction of highly charged Ne ions with an Al(110) surface
Physical Review A, 1994
We studied the potential electron emission arising from the interaction of H-like Ne + jons with clean Al(110) and Pt(110) surfaces at different glancing angles (10'-90') with 90-keV impact energy. Projectile KLL Auger electrons are found to be emitted from inside the solid. Therefore, the measured electron energy distributions are inQuenced by solid-state effects. We present a deconvolution procedure to determine the scattering contribution to the measured spectra for Al targets. After a subtraction of the scattering contribution we compare the resulting primary emission spectra with atomic structure calculations. The calculations show that at the moment of KLL Auger electron emission the projectile L shell is completely 61led for an Al target, whereas for a Pt target there were on the average only Bve electrons in the projectile L-shell. This indicates a relatively faster L-shell 61ling process for Al targets.
Comparative analysis of the low-energy He+ ions scattering on Al and Al2O3 surfaces
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
Using the Anderson±Muda±Newns approach, the neutralization rate and the ion survival probability have been calculated for the large angle scattering of low-energy He ions by Al and by Al 2 O 3. The two-band model of the electronic energy spectra is applied for the case of alumina. The electron promotion has been shown to play an important role in the processes of the He ions scattering by aluminum and alumina. The experimentally observed absence of the matrix eect is discussed on the basis of the obtained results.
Physical Review A, 2011
A joint experimental and theoretical study of energy loss is presented for 1-to-4-keV fluorine negative ions in grazing scattering on a missing-row reconstructed Au(110) surface. Measurements of energy losses for various azimuthal orientations of the crystal have been performed by means of a time-of-flight method with a pulsed beam. The dependence of the fraction of surviving negative ions on azimuthal angles, was determined. Our energy-loss data are discussed in light of trajectory and stopping-power calculations, where the explicit inclusion of the nonuniform electron density at the surface provides good agreement with the experimental data. The simulation allows us to delineate various trajectory classes that correspond to different contributions in the energy-loss spectra for various azimuthal orientations of the surface.
Low energy He, Ne and Ar ion scattering from metal surfaces: Background and inelastic effects
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1988
The 139' ion scattering spectra of He, Ne and Ar ions incident on polycrystalline W, Ta and Au are measured for incident energies ranging from 0.8 keV to 4 keV. The He+ and Ar+ scattering behaviour from W is found to be very similar to that from Ta and different from that from Au. The single collision peak is shifted of about 20 eV to lower energy when calibrated with the Au single collision peak and for He+ scattering an important background contribution increasing with the incident energy is observed. These results cannot be explained by structure effects in the first atomic planes is revealed by simulation. They relate rather to differences in the charged fraction of ions scattered from inside the solid. This is interpreted on the basis of reionization at metal surfaces having a high density of electronic states above the Fermi level.
The role of atomic collisions in kinetic electron emission from Al surfaces by slow ions
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2007
We measured energy distributions of electrons emitted in the interaction of slow Kr + and Na + with Al surfaces. The data allow to correlate emission intensities with spectral signatures of electron excitation processes. Our results indicate that electron promotion processes leading to the excitation of Al target atoms plays the dominating role in kinetic electron emission from Al surfaces by slow ions. In the case of Kr + ions, electron promotion occurs in close atomic collisions between recoiling target atoms. For Na + projectiles, a significant contribution to Al excitation comes also from a vacancy transfer process in asymmetric collisions involving ions that have survived neutralization in the interaction with the surface.
H− formation in the scattering of hydrogen ions on an Al surface
Surface Science, 1996
We present results of an experimental and theoretical investigation of H-formation in collisions of 1-4 keV positive and negative hydrogen ions with clean A1 surfaces. The scattered ion fractions were investigated in a large angular range extending from 2 to 40 ° with respect to the surface plane. This allowed us to investigate the characteristics of the resonant charge transfer process in a wide range of collision velocities normal to the surface, allowing us in particular to reach the domain where small atom-surface distances play an important role. Results of theoretical calculations could thus be tested in a more stringent manner than in previous high grazing-incidence experiments of Wyputta et al.
Scattering of light keV ions from amorphous and crystalline solid surfaces
Nuclear Instruments and Methods, 1976
Total reflection coefficients (R), backscattered energy fractions (~,), and backscattered energy spectra are evaluated using a binary collision Monte Carlo technique for a variety of light ions (H, D, T, He) in the energy range 0.25-8 keV, incident on amorphous targets (C, Fe, Nb). The scattering is also evaluated for H on Nb for a range of incident angles and two electronic stopping values. The average scattered energy per reflected particle and the backscattered energy spectra are found to vary in a universal manner as a function of the reflection coefficient between the Rutherford high energy limit and a low energy multiple collision limit. Single crystal effects are also briefly discussed using a diffusional dechanneling model.