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N Stolterfoht - One of the best experts on this subject based on the ideXlab platform.
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k Auger Electron Emission from hollow ne atoms in solids
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 1996Co-Authors: M Grether, R Kohrbruck, A Arnau, A Spieler, N StolterfohtAbstract:Abstract We studied the K Auger Emission of hollow Ne atoms in an Al solid using the recently developed multiple cascade model that describes the filling of inner shells of highly charged ions in solids. In particular we have taken into account the KLC Auger transition that occurs early in the filling sequence of the hollow atom. In the KLC Auger process the emitted Electrons originate from the induced screening cloud (C) that surrounds the highly charged ion in the solid. The KLC Auger Electrons appear in the measured Electron spectra well separated at the high energy side of the KLL Auger peak. From the comparison of the experiment and the model we obtain a fair estimate of the KLC Auger rate.
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Auger Electron Emission following double Electron capture in 150 kev ne10 he collisions
Physical Review A, 1994Co-Authors: F Fremont, H Merabet, J Y Chesnel, X Husson, A Lepoutre, D Lecler, G Rieger, N StolterfohtAbstract:The method of projectile Electron spectroscopy was used to measure the Ne[sup 8+] Auger decay of the configurations 3[ital lnl][prime] and 4[ital lnl][prime] ([ital n][ge]4) created by double Electron capture in 150-keV Ne[sup 10+]+He collisions. Auger yields were evaluated to convert the experimental cross sections for Auger-Electron Emission into the corresponding cross sections for double Electron capture. It is found that the cross sections attributed to the configurations 3[ital lnl][prime] follow a [ital n][sup [minus]3] law, while the excitation of the configurations 4[ital lnl][prime] is rather selective for [ital n]=5. It is shown by means of model calculations that the Electron correlation plays a decisive role in the capture mechanisms producing the configurations 3[ital lnl][prime].
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excitation of target Auger Electron Emission by the impact of highly charged ions n6 o7 and ne9 on pt 110
Physical Review A, 1992Co-Authors: S Schippers, D Lecler, S Hustedt, W Heiland, R Kohrbruck, J Bleckneuhaus, J Kemmler, N StolterfohtAbstract:We studied the interaction of highly charged ions on metal surfaces leading to the Emission of Electrons from the projectile and from the target. The target Electrons are due to potential Emission, kinetic Emission, and Auger-Electron Emission. In our Electron spectra two types of target Auger Electrons are distinguished. Electrons near 135 and 220 eV are ascribed to Pt {ital N}{sub 45}{ital O1}{ital O23} and {ital N}{sub 45}{ital N67}{ital V} Auger transitions. They are caused by {ital K}-vacancy transfer into the Pt {ital N} shell and are only emitted under bombardment with N{sup 6+} and O{sup 7+}. The other type of Electrons near 40 and 60 eV are ascribed to Pt {ital O}{sub 23}{ital VV} and {ital N}{sub 67}{ital VV} Auger transitions. They are due to direct ionization and are emitted under bombardment with each projectile used. According to our analysis, the initial projectile {ital K}-shell vacancy survives the transport to and at least 8{times}10{sup {minus}16} s within the target surface.
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angular distribution of Auger Electron Emission following double Electron capture in c6 he collisions
Physical Review A, 1992Co-Authors: F Fremont, X Husson, D Lecler, K Sommer, S Hicham, P Boduch, N StolterfohtAbstract:Angular distributions of Auger Electrons ejected in 60-keV C{sup 6+}+He collisions were measured. This study extends previous work where cross sections for the production of the configuration 2{ital lnl}{prime} ({ital n}{ge}3) have been determined from measurements at the observation angle of 0{degree} only. For {ital n}=3 and 4, the present angular distributions were measured to be anisotropic, whereas for {ital n}=5 and 6 the Electron Emissions were found to be isotropic within the experimental uncertainties. The integration over the observation angle yields total production cross sections {sigma}{sub 2{ital l}{ital n}{ital l}} that were found to follow an {ital n}{sup {minus}3} law, in agreement with previous calculations. The observed angular distributions are discussed in terms of different capture mechanisms.
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Auger Electron Emission from slow highly charged ions interacting with solid cu targets
Physical Review A, 1992Co-Authors: R Kohrbruck, J P Biersack, F Fremont, D Lecler, S Schippers, J Bleckneuhaus, K Sommer, P Roncin, N StolterfohtAbstract:Secondary-Electron energy spectra were measured for ${\mathrm{Ar}}^{\mathit{q}+}$ (q=9 and 16) and the H-like ions ${\mathrm{N}}^{6+}$, ${\mathrm{O}}^{7+}$, and ${\mathrm{Ne}}^{9+}$, incident on solid Cu surfaces at an angle of 10\ifmmode^\circ\else\textdegree\fi{}. The impact energy was varied from 10q to 20q keV. Auger Electrons were detected at various observation angles from 20\ifmmode^\circ\else\textdegree\fi{} to 180\ifmmode^\circ\else\textdegree\fi{} with respect to the incident beam. From the Doppler shift of the projectile Auger Electrons, the L Auger Electrons of argon and neon are found to be emitted from ions whose flight direction is parallel to the incident beam and the K Auger Electrons of nitrogen, oxygen, and neon are observed to be emitted from deflected ions. Evidence is provided for incident ${\mathrm{Ne}}^{9+}$ and ${\mathrm{Ar}}^{16+}$ that the L shells are incompletely filled when the projectiles reach the surface. The data analysis is supported by model calculations.
D Lecler - One of the best experts on this subject based on the ideXlab platform.
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Auger Electron Emission following double Electron capture in 150 kev ne10 he collisions
Physical Review A, 1994Co-Authors: F Fremont, H Merabet, J Y Chesnel, X Husson, A Lepoutre, D Lecler, G Rieger, N StolterfohtAbstract:The method of projectile Electron spectroscopy was used to measure the Ne[sup 8+] Auger decay of the configurations 3[ital lnl][prime] and 4[ital lnl][prime] ([ital n][ge]4) created by double Electron capture in 150-keV Ne[sup 10+]+He collisions. Auger yields were evaluated to convert the experimental cross sections for Auger-Electron Emission into the corresponding cross sections for double Electron capture. It is found that the cross sections attributed to the configurations 3[ital lnl][prime] follow a [ital n][sup [minus]3] law, while the excitation of the configurations 4[ital lnl][prime] is rather selective for [ital n]=5. It is shown by means of model calculations that the Electron correlation plays a decisive role in the capture mechanisms producing the configurations 3[ital lnl][prime].
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excitation of target Auger Electron Emission by the impact of highly charged ions n6 o7 and ne9 on pt 110
Physical Review A, 1992Co-Authors: S Schippers, D Lecler, S Hustedt, W Heiland, R Kohrbruck, J Bleckneuhaus, J Kemmler, N StolterfohtAbstract:We studied the interaction of highly charged ions on metal surfaces leading to the Emission of Electrons from the projectile and from the target. The target Electrons are due to potential Emission, kinetic Emission, and Auger-Electron Emission. In our Electron spectra two types of target Auger Electrons are distinguished. Electrons near 135 and 220 eV are ascribed to Pt {ital N}{sub 45}{ital O1}{ital O23} and {ital N}{sub 45}{ital N67}{ital V} Auger transitions. They are caused by {ital K}-vacancy transfer into the Pt {ital N} shell and are only emitted under bombardment with N{sup 6+} and O{sup 7+}. The other type of Electrons near 40 and 60 eV are ascribed to Pt {ital O}{sub 23}{ital VV} and {ital N}{sub 67}{ital VV} Auger transitions. They are due to direct ionization and are emitted under bombardment with each projectile used. According to our analysis, the initial projectile {ital K}-shell vacancy survives the transport to and at least 8{times}10{sup {minus}16} s within the target surface.
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angular distribution of Auger Electron Emission following double Electron capture in c6 he collisions
Physical Review A, 1992Co-Authors: F Fremont, X Husson, D Lecler, K Sommer, S Hicham, P Boduch, N StolterfohtAbstract:Angular distributions of Auger Electrons ejected in 60-keV C{sup 6+}+He collisions were measured. This study extends previous work where cross sections for the production of the configuration 2{ital lnl}{prime} ({ital n}{ge}3) have been determined from measurements at the observation angle of 0{degree} only. For {ital n}=3 and 4, the present angular distributions were measured to be anisotropic, whereas for {ital n}=5 and 6 the Electron Emissions were found to be isotropic within the experimental uncertainties. The integration over the observation angle yields total production cross sections {sigma}{sub 2{ital l}{ital n}{ital l}} that were found to follow an {ital n}{sup {minus}3} law, in agreement with previous calculations. The observed angular distributions are discussed in terms of different capture mechanisms.
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Auger Electron Emission from slow highly charged ions interacting with solid cu targets
Physical Review A, 1992Co-Authors: R Kohrbruck, J P Biersack, F Fremont, D Lecler, S Schippers, J Bleckneuhaus, K Sommer, P Roncin, N StolterfohtAbstract:Secondary-Electron energy spectra were measured for ${\mathrm{Ar}}^{\mathit{q}+}$ (q=9 and 16) and the H-like ions ${\mathrm{N}}^{6+}$, ${\mathrm{O}}^{7+}$, and ${\mathrm{Ne}}^{9+}$, incident on solid Cu surfaces at an angle of 10\ifmmode^\circ\else\textdegree\fi{}. The impact energy was varied from 10q to 20q keV. Auger Electrons were detected at various observation angles from 20\ifmmode^\circ\else\textdegree\fi{} to 180\ifmmode^\circ\else\textdegree\fi{} with respect to the incident beam. From the Doppler shift of the projectile Auger Electrons, the L Auger Electrons of argon and neon are found to be emitted from ions whose flight direction is parallel to the incident beam and the K Auger Electrons of nitrogen, oxygen, and neon are observed to be emitted from deflected ions. Evidence is provided for incident ${\mathrm{Ne}}^{9+}$ and ${\mathrm{Ar}}^{16+}$ that the L shells are incompletely filled when the projectiles reach the surface. The data analysis is supported by model calculations.
A Bonanno - One of the best experts on this subject based on the ideXlab platform.
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the role of al Auger Electrons in kinetic Electron Emission from al surfaces by slow ne and na ions
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2007Co-Authors: M Minniti, A Bonanno, A Oliva, P Barone, M Commisso, A Sindona, P RiccardiAbstract:This work reports measurements of energy distributions and yields of Electrons emitted in the interaction of slow singly charged neon and sodium ions with Al surfaces. The measurements show the strong interplay between different Emission mechanisms, such as projectile and target Auger Electron Emission, decay of bulk plasmons and Electronic collision cascade. These results indicate that the Auger decay of Al-2p excitations occurring in binary atomic collision between recoiling target atoms, is the dominant primary excitation mechanism. Measurements performed using sodium projectile show that a significant contribution to the total Electron Emission yield comes also from a vacancy transfer process that produce Al-2p excitation by a vacancy transfer process in asymmetric collisions between target atoms and incoming ions that have survived neutralization at the surface.
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Auger Electron Emission in the interaction of slow na ions with al surfaces
Radiation Physics and Chemistry, 2007Co-Authors: P Barone, A Bonanno, A Oliva, M Commisso, M Minniti, P RiccardiAbstract:Abstract We present energy distributions of Electrons emitted in the interaction of Na + ions with Al surfaces as a function of incident ion energy in the range 300–2000 eV. We discuss the Auger spectra of Sodium, which show several lines due to decay in vacuum of projectiles, singly and doubly excited in the 2p shell by Electron promotion in close encounters with target atoms. Our results indicate that the double vacancy production is in close relation with the Al–2p Electron excitation via an autoexcitation mechanism.
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ion induced atomic like lmm and l2mm Auger Electron Emission from mg al si and mgxal1 x role of symmetric and asymmetric collisions
Physical Review B, 1993Co-Authors: F Ascione, N Mandarino, P Zoccali, A Bonanno, Patrizia Calaminici, A Oliva, Nino RussoAbstract:We present a detailed study on Auger-Electron Emission from sputtered light-target atomic species (Mg, Al, and Si) with one and two initial 2p core vacancies by low-energy (2-15 keV) noble-gas-ion bombardment on elemental and Mg x Al 1-x alloy samples. We show that the Al atomic LMM peak shape varies sensitively with primary energy for Ar + but not for Ne + , Kr + , and Xe + projectiles, that the high-energy spectral regions of all three elements consist of many previously unresolved atomic line structures, and that the L 2 MM-to-LMM intensity ratio depends on both primary ion energy and incidence angle. Adiabatic molecular-orbital correlation diagrams are also computed for describing the 2p core-Electron promotion
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al atomic Auger Electron Emission from low kev ion bombarded al surfaces
Physical Review A, 1992Co-Authors: N Mandarino, P Zoccali, A BonannoAbstract:Al atomic {ital LMM} Auger Electron Emission from clean and oxygen- or argon-covered Al surfaces has been studied for low-keV Ar{sup +}-ion bombardment along normal and off-normal incidence directions. We show that, for a clean Al surface, many transitions are suppressed by the surface-neutralization process and that the quenching of such a neutralization mechanism and the activation of a surface-ionization mechanism by oxygen chemisorption or argon physisorption can unveil these hidden peaks. Our results provide some insights into the peculiarities of ion-solid interactions and offer an interesting explanation to the observed large difference in the relative transition ratios in experiments with solid and gas targets.
A R Koymen - One of the best experts on this subject based on the ideXlab platform.
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Auger Electron Emission initiated by the creation of valence band holes in graphene by positron annihilation
Nature Communications, 2017Co-Authors: V A Chirayath, Vincent Callewaert, A J Fairchild, M D Chrysler, R W Gladen, A D Mcdonald, S K Imam, K Shastry, A R KoymenAbstract:Auger processes are at the core of Electron Emission in solid-state physics, however measuring the spectra of Electrons emitted solely as a result of Auger transitions remains a challenge. Here, the authors measure the Electron energy spectrum in graphene and observe the…
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Auger Electron Emission initiated by the creation of valence band holes in graphene by positron annihilation
Nature Communications, 2017Co-Authors: V A Chirayath, Vincent Callewaert, A J Fairchild, M D Chrysler, R W Gladen, A D Mcdonald, S K Imam, K Shastry, A R KoymenAbstract:Auger processes involving the filling of holes in the valence band are thought to make important contributions to the low-energy photoElectron and secondary Electron spectrum from many solids. However, measurements of the energy spectrum and the efficiency with which Electrons are emitted in this process remain elusive due to a large unrelated background resulting from primary beam-induced secondary Electrons. Here, we report the direct measurement of the energy spectra of Electrons emitted from single layer graphene as a result of the decay of deep holes in the valence band. These measurements were made possible by eliminating competing backgrounds by employing low-energy positrons (<1.25 eV) to create valence-band holes by annihilation. Our experimental results, supported by theoretical calculations, indicate that between 80 and 100% of the deep valence-band holes in graphene are filled via an Auger transition.
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measurement of positron annihilation induced Auger Electron Emission from fe cu pd and au
Surface Science, 1992Co-Authors: K H Lee, A R Koymen, D Mehl, Kjeld O Jensen, A H WeissAbstract:Abstract Positron annihilation induced Auger Electron spectroscopy (PAES) makes use of Electron-positron annihilation to create core holes which result in Auger Electron Emission. This excitation process provides PAES with significantly higher surface selectivity than conventional Auger techniques. To date, PAES measurements have been reported on 5 elements. In this paper we report the first positron annihilation measurements of Pd and Au along with measurements of Cu and Fe. Analysis of the data indicates that the intensities of the low energy Auger signals of Cu, Fe, Pd, and Au are in the proportion of 1.00:0.57:1.35:1.17. These measurements should be useful in providing elemental standards for investigations of epitaxial growth and/or intermixing in bimetallic systems. The measured intensities are compared to calculations for core annihilation probabilities. In addition, measurements which demonstrate the sensitivity of PAES to H2 chemisorption on Pd are presented.
F Fremont - One of the best experts on this subject based on the ideXlab platform.
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Auger Electron Emission following double Electron capture in 150 kev ne10 he collisions
Physical Review A, 1994Co-Authors: F Fremont, H Merabet, J Y Chesnel, X Husson, A Lepoutre, D Lecler, G Rieger, N StolterfohtAbstract:The method of projectile Electron spectroscopy was used to measure the Ne[sup 8+] Auger decay of the configurations 3[ital lnl][prime] and 4[ital lnl][prime] ([ital n][ge]4) created by double Electron capture in 150-keV Ne[sup 10+]+He collisions. Auger yields were evaluated to convert the experimental cross sections for Auger-Electron Emission into the corresponding cross sections for double Electron capture. It is found that the cross sections attributed to the configurations 3[ital lnl][prime] follow a [ital n][sup [minus]3] law, while the excitation of the configurations 4[ital lnl][prime] is rather selective for [ital n]=5. It is shown by means of model calculations that the Electron correlation plays a decisive role in the capture mechanisms producing the configurations 3[ital lnl][prime].
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angular distribution of Auger Electron Emission following double Electron capture in c6 he collisions
Physical Review A, 1992Co-Authors: F Fremont, X Husson, D Lecler, K Sommer, S Hicham, P Boduch, N StolterfohtAbstract:Angular distributions of Auger Electrons ejected in 60-keV C{sup 6+}+He collisions were measured. This study extends previous work where cross sections for the production of the configuration 2{ital lnl}{prime} ({ital n}{ge}3) have been determined from measurements at the observation angle of 0{degree} only. For {ital n}=3 and 4, the present angular distributions were measured to be anisotropic, whereas for {ital n}=5 and 6 the Electron Emissions were found to be isotropic within the experimental uncertainties. The integration over the observation angle yields total production cross sections {sigma}{sub 2{ital l}{ital n}{ital l}} that were found to follow an {ital n}{sup {minus}3} law, in agreement with previous calculations. The observed angular distributions are discussed in terms of different capture mechanisms.
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Auger Electron Emission from slow highly charged ions interacting with solid cu targets
Physical Review A, 1992Co-Authors: R Kohrbruck, J P Biersack, F Fremont, D Lecler, S Schippers, J Bleckneuhaus, K Sommer, P Roncin, N StolterfohtAbstract:Secondary-Electron energy spectra were measured for ${\mathrm{Ar}}^{\mathit{q}+}$ (q=9 and 16) and the H-like ions ${\mathrm{N}}^{6+}$, ${\mathrm{O}}^{7+}$, and ${\mathrm{Ne}}^{9+}$, incident on solid Cu surfaces at an angle of 10\ifmmode^\circ\else\textdegree\fi{}. The impact energy was varied from 10q to 20q keV. Auger Electrons were detected at various observation angles from 20\ifmmode^\circ\else\textdegree\fi{} to 180\ifmmode^\circ\else\textdegree\fi{} with respect to the incident beam. From the Doppler shift of the projectile Auger Electrons, the L Auger Electrons of argon and neon are found to be emitted from ions whose flight direction is parallel to the incident beam and the K Auger Electrons of nitrogen, oxygen, and neon are observed to be emitted from deflected ions. Evidence is provided for incident ${\mathrm{Ne}}^{9+}$ and ${\mathrm{Ar}}^{16+}$ that the L shells are incompletely filled when the projectiles reach the surface. The data analysis is supported by model calculations.