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Gnaser H, Martschini M, Leimbach D, Karls J, Hanstorp D, Indrajith S, Ji M, Martini P, Simonsson A, Zettergren H, Schmidt HT, Golser R. Spontaneous and photo-induced decay processes of WF 5 - and HfF 5 - molecular anions in a cryogenic storage ring. J Chem Phys 2022; 157:044304. [PMID: 35922356 DOI: 10.1063/5.0097896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Spontaneous and photo-induced decay processes of HfF5 - and WF5 - molecular anions were investigated in the Double ElectroStatic Ion Ring ExpEriment (DESIREE). The observation of these reactions over long time scales (several tens of ms) was possible due to the cryogenic temperatures (13 K) and the extremely low residual gas pressure (∼10-14 mbar) of DESIREE. For photo-induced reactions, laser wavelengths in the range 240 to 450 nm were employed. Both anion species were found to undergo spontaneous decay via electron detachment or fragmentation. After some ms, radiative cooling processes were observed to lower the probability for further decay through these processes. Photo-induced reactions indicate the existence of an energy threshold for WF5 - anions at about 3.5 eV, above which the neutralization yield increases strongly. By contrast, HfF5 - ions exhibit essentially no enhanced production of neutrals upon photon interaction, even for the highest photon energy used in this experiment (∼5.2 eV). This suppression will be highly beneficial for the efficient detection, in accelerator mass spectrometry, of the extremely rare isotope 182Hf using the 182HfF5 - anion while effectively reducing the interfering stable isobar 182W in the analyte ion 182WF5 -. The radionuclide 182Hf is of great relevance in astrophysical environments as it constitutes a potential candidate to study the events of nucleosynthesis that may have taken place in the vicinity of the solar system several million years ago.
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Affiliation(s)
- Hubert Gnaser
- University of Vienna, Faculty of Physics, Isotope Physics - VERA Laboratory, A-1090 Wien, Austria
| | - Martin Martschini
- University of Vienna, Faculty of Physics, Isotope Physics - VERA Laboratory, A-1090 Wien, Austria
| | - David Leimbach
- Department of Physics, University of Gothenburg, SE-41296 Gothenburg, Sweden
| | - Julia Karls
- Department of Physics, University of Gothenburg, SE-41296 Gothenburg, Sweden
| | - Dag Hanstorp
- Department of Physics, University of Gothenburg, SE-41296 Gothenburg, Sweden
| | | | - Mingchao Ji
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Paul Martini
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Ansgar Simonsson
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | | | - Henning T Schmidt
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Robin Golser
- University of Vienna, Faculty of Physics, Isotope Physics - VERA Laboratory, A-1090 Wien, Austria
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Sergievskaya A, Chauvin A, Konstantinidis S. Sputtering onto liquids: a critical review. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2022; 13:10-53. [PMID: 35059275 PMCID: PMC8744456 DOI: 10.3762/bjnano.13.2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 12/07/2021] [Indexed: 05/03/2023]
Abstract
Sputter deposition of atoms onto liquid substrates aims at producing colloidal dispersions of small monodisperse ultrapure nanoparticles (NPs). Since sputtering onto liquids combines the advantages of the physical vapor deposition technique and classical colloidal synthesis, the review contains chapters explaining the basics of (magnetron) sputter deposition and the formation of NPs in solution. This review article covers more than 132 papers published on this topic from 1996 to September 2021 and aims at providing a critical analysis of most of the reported data; we will address the influence of the sputtering parameters (sputter power, current, voltage, sputter time, working gas pressure, and the type of sputtering plasma) and host liquid properties (composition, temperature, viscosity, and surface tension) on the NP formation as well as a detailed overview of the properties and applications of the produced NPs.
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Affiliation(s)
- Anastasiya Sergievskaya
- Plasma-Surface Interaction Chemistry (ChIPS), University of Mons, 23 Place du Parc, B-7000 Mons, Belgium
| | - Adrien Chauvin
- Plasma-Surface Interaction Chemistry (ChIPS), University of Mons, 23 Place du Parc, B-7000 Mons, Belgium
- Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Praha 2, Czech Republic
| | - Stephanos Konstantinidis
- Plasma-Surface Interaction Chemistry (ChIPS), University of Mons, 23 Place du Parc, B-7000 Mons, Belgium
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Anderson EK, Schmidt-May AF, Najeeb PK, Eklund G, Chartkunchand KC, Rosén S, Larson Å, Hansen K, Cederquist H, Zettergren H, Schmidt HT. Spontaneous Electron Emission from Hot Silver Dimer Anions: Breakdown of the Born-Oppenheimer Approximation. PHYSICAL REVIEW LETTERS 2020; 124:173001. [PMID: 32412256 DOI: 10.1103/physrevlett.124.173001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 03/15/2020] [Accepted: 04/09/2020] [Indexed: 06/11/2023]
Abstract
We report the first experimental evidence of spontaneous electron emission from a homonuclear dimer anion through direct measurements of Ag_{2}^{-}→Ag_{2}+e^{-} decays on milliseconds and seconds timescales. This observation is very surprising as there is no avoided crossing between adiabatic energy curves to mediate such a process. The process is weak, yet dominates the decay signal after 100 ms when ensembles of internally hot Ag_{2}^{-} ions are stored in the cryogenic ion-beam storage ring, DESIREE, for 10 s. The electron emission process is associated with an instantaneous, very large reduction of the vibrational energy of the dimer system. This represents a dramatic deviation from a Born-Oppenheimer description of dimer dynamics.
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Affiliation(s)
- E K Anderson
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - A F Schmidt-May
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, A-6020 Innsbruck, Austria
| | - P K Najeeb
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - G Eklund
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - K C Chartkunchand
- Atomic, Optical, and Molecular Physics Laboratory, RIKEN Cluster for Pioneering Research Wako-shi, Saitama 351-0198, Japan
| | - S Rosén
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - Å Larson
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - K Hansen
- Center for Joint Quantum Studies and Department of Physics, Tianjin University, 92 Weijin Road, Tianjin 300072, China
- Department of Physics, University of Gothenburg, 41296 Gothenburg, Sweden
| | - H Cederquist
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - H Zettergren
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - H T Schmidt
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
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Breitenfeldt C, Blaum K, George S, Göck J, Guzmán-Ramírez G, Karthein J, Kolling T, Lange M, Menk S, Meyer C, Mohrbach J, Niedner-Schatteburg G, Schwalm D, Schweikhard L, Wolf A. Long-Term Monitoring of the Internal Energy Distribution of Isolated Cluster Systems. PHYSICAL REVIEW LETTERS 2018; 120:253001. [PMID: 29979073 DOI: 10.1103/physrevlett.120.253001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 04/05/2018] [Indexed: 06/08/2023]
Abstract
A method is presented to monitor the internal energy distribution of cluster anions via delayed electron detachment by pulsed photoexcitation and demonstrated on Co_{4}^{-} in an electrostatic ion beam trap. In a cryogenic operation, we calibrate the detachment delay to internal energy. By laser frequency scans, at room temperature, we reconstruct the time-dependent internal energy distribution of the clusters. The mean energies of ensembles from a cold and a hot ion source both approach thermal equilibrium. Our data yield a radiative emission law and the absorptivity of the cluster for thermal radiation.
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Affiliation(s)
- Christian Breitenfeldt
- Institut für Physik, Universität Greifswald, 17487 Greifswald, Germany
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - Klaus Blaum
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | | | - Jürgen Göck
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - Gregorio Guzmán-Ramírez
- Departamento de Ingenierías, Centro Universitario de Tonalá, Universidad de Guadalajara, Jal. 48525, Mexico
| | - Jonas Karthein
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - Thomas Kolling
- Fachbereich Chemie and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Michael Lange
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - Sebastian Menk
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - Christian Meyer
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
| | - Jennifer Mohrbach
- Fachbereich Chemie and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Gereon Niedner-Schatteburg
- Fachbereich Chemie and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Dirk Schwalm
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
- Department of Particle Physics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Lutz Schweikhard
- Institut für Physik, Universität Greifswald, 17487 Greifswald, Germany
| | - Andreas Wolf
- Max-Planck-Institut für Kernphysik, 69117 Heidelberg, Germany
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Mane R, Mehrotra N, Maity DK, Gupta AK. On the formation of SFn (-) (n = 1-6) anions via a novel route and their properties. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:1317-1327. [PMID: 26405793 DOI: 10.1002/rcm.7225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 05/07/2015] [Accepted: 05/07/2015] [Indexed: 06/05/2023]
Abstract
RATIONALE Sulfur hexafluoride (SF6 ) being a potential greenhouse gas, coupled with its numerous applications, makes the study of the formation and fragmentation of SF6 -based species important. The formation of SF6 -based anionic species has been studied using the gas feed-sputtering route and the mechanisms at play during the sputter-ejection of guest molecule-derived particles have also been probed. METHODS Studies of the formation of SFn (-) (n = 1-6) anions were conducted from various surfaces (metal and compound) that were subjected to Cs(+) ion sputtering in the presence of SF6 gas employing the gas feed-cesium sputter technique. The anions generated were mass analyzed using a double-focusing magnetic sector mass spectrometer. Quantum mechanical computations were performed to study the ground state structure and stability of neutral and negatively charged SFn (n = 1-6) systems applying density functional theory (DFT) and ab initio methods (MP2 and CC). RESULTS This technique readily generated (32) SFn (-) (n = 1-6) anions for all sizes of 'n' with practicable yields. Mass spectrometric measurements of the yield of sputter-ejected (32) SFn (-) (n = 1-6) anions reveal an oscillatory pattern as a function of 'n', with odd values of 'n' being relatively more abundant. The relative yield of (34) SFn (-) (n = 1-6) anions with respect to size was also measured albeit with low signal intensity. Also observed were F(-) , S(-) , F2 (-) , (33) SF5 (-) and (33) SF6 (-) anionic species. The relevant electron affinity and bond dissociation energy (BDE) values were also computed. CONCLUSIONS Gas-phase SFn (-) (n = 1-6) anions can be effectively generated by using the gas spray-cesium sputter technique. Both experimental measurements and calculations indicate the existence of odd-even oscillations in the stability and electronic structure of the SFn (n = 1-6) systems. The highest yield recorded was for the sputter-ejected SF5 (-) species and this may be attributed to its 'superhalogen' anionic character coupled with the relatively favorable F(0) fragmentation pathway of sputtered SF6 (-) . A signature pertaining to intact SF6 (-) anion ejection is also observed.
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Affiliation(s)
- Rupali Mane
- Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - Nitin Mehrotra
- Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - Dilip K Maity
- Theoretical Chemistry Section, Bhabha Atomic Research Centre, Mumbai, 400085, India
- Homi Bhabha National Institute, Training School Complex, Mumbai, 400094, India
| | - Anit K Gupta
- Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
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6
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Weidtmann B, Duvenbeck A, Wucher A. Does local disorder influence secondary ion formation? SURF INTERFACE ANAL 2014. [DOI: 10.1002/sia.5506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Boris Weidtmann
- Faculty of Physics; University of Duisburg-Essen; D-47048 Duisburg Germany
| | - Andreas Duvenbeck
- Faculty of Physics; University of Duisburg-Essen; D-47048 Duisburg Germany
| | - Andreas Wucher
- Faculty of Physics; University of Duisburg-Essen; D-47048 Duisburg Germany
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Fišer J, Diez RP, Franzreb K, Alonso JA. Comment on “The diatomic dication CuZn 2+ in the gas phase” [J. Chem. Phys. 135, 034306 (2011)]. J Chem Phys 2013; 138:077101. [DOI: 10.1063/1.4791759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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9
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Postawa Z, Czerwinski B, Winograd N, Garrison BJ. Microscopic Insights into the Sputtering of Thin Organic Films on Ag{111} Induced by C60 and Ga Bombardment. J Phys Chem B 2005; 109:11973-9. [PMID: 16852476 DOI: 10.1021/jp050821w] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecular dynamics computer simulations have been employed to model the bombardment of Ag{111} covered with three layers of C6H6 by 15 keV Ga and C60 projectiles. The study is aimed toward examining the mechanism by which molecules are desorbed from surfaces by energetic cluster ion beams and toward elucidating the differences between cluster bombardment and atom bombardment. The results show that the impact of the cluster on the benzene-covered surface leads to molecular desorption during the formation of a mesoscopic scale impact crater via a catapulting mechanism. Because of the high yield of C6H6 with both Ga and C60, the yield enhancement is observed to be consistent with related experimental observations. Specific energy and angle distributions are shown to be associated with the catapult mechanism.
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Affiliation(s)
- Zbigniew Postawa
- Smoluchowski Institute of Physics, Jagiellonian University, Krakow, Poland.
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Postawa Z, Czerwinski B, Szewczyk M, Smiley EJ, Winograd N, Garrison BJ. Microscopic Insights into the Sputtering of Ag{111} Induced by C60and Ga Bombardment. J Phys Chem B 2004. [DOI: 10.1021/jp049936a] [Citation(s) in RCA: 169] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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11
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Betz G, Husinsky W. Modelling of cluster emission from metal surfaces under ion impact. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2004; 362:177-194. [PMID: 15306283 DOI: 10.1098/rsta.2003.1302] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Using the molecular-dynamics technique, cluster emission for 5 keV Ar bombardment of a Cu (111) surface has been investigated using a many-body (tight binding) potential for the Cu-Cu interaction. The calculations allow us to analyse the basic processes underlying cluster emission. It is found that two distinct processes can be distinguished which lead to cluster emission under energetic ion bombardment. The first process causes the emission of small clusters, which are emitted by a collective motion during the development of the collision cascade within the first picosecond after impact. Thus, emission times of such clusters agree with the emission times of atoms in sputtering. Such a process can be envisioned if, for example, a few layers below the surface, an energetic recoil causes the development of a subcascade. Energy transferred by this event to the surface is strongly directional and can lead to the simultaneous emission of a group of neighbouring surface atoms, which in some cases will remain bounded and form a cluster after emission. Typically, clusters emitted by this mechanism consist of atoms, which are neighbouring in the target and are almost exclusively surface atoms, similar to all sputtered atoms. Emission of large clusters (cluster sizes of 10 or more atoms), as observed experimentally, is a puzzling phenomenon. From our calculations we conclude that the emission of such large clusters does not occur during the collisional phase of sputtering, but happens much later (5-10 ps after ion impact). Emission can occur for spike events, where all the energy of the impinging ion is deposited locally in a small volume near to the surface, and the sputtering yield is 3-5 times the average yield. Such events are rare, but we have found a few cases in our calculations where stable clusters consisting of more than 20 atoms were emitted. Melting of the spike volume occurs, and the high temperatures and pressures produced can cause emission of large fragments during the thermal phase. The composition of such large clusters is quite different from that of small clusters. They consist of atoms from different layers and the constituents are also generally not next-neighbour atoms. This change in origin of the cluster atoms reflects the mixing and diffusion processes occurring in the melted zone before emission. The calculations indicate that hydrodynamical phenomena might play a role in the emission of large fragments. Additional calculations, where the energy was distributed 'thermally' in a three-dimensional volume under the surface for 500 fs, give very similar results, even in such cases where the kinetic phase of the collision-cascade development was absent.
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Affiliation(s)
- G Betz
- Institut für Allgemeine Physik, Technische Universität Wien, Wiedner Hauptstrasse 8-10, 1040 Wien, Austria.
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Smith R, Kenny SD, Ramasawmy D. Molecular-dynamics simulations of sputtering. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2004; 362:157-176. [PMID: 15306282 DOI: 10.1098/rsta.2003.1308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The use of molecular-dynamics simulations to understand the ejection processes of particles from surfaces after energetic ion bombardment is discussed. Substrates considered include metals, covalent and ionic materials, polymers and molecular solids. It is shown how the simulations can be used to aid interpretation of experimental results by providing the underlying mechanisms behind the ejection processes.
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Affiliation(s)
- Roger Smith
- Department of Mathematical Sciences, Loughborough University, Loughborough LE11 3TU, UK.
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Pan L, Rao BK, Gupta AK, Das GP, Ayyub P. H-substituted anionic carbon clusters CnH− (n⩽10): Density functional studies and experimental observations. J Chem Phys 2003. [DOI: 10.1063/1.1609400] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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14
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Lindenblatt M, Heinrich R, Wucher A, Garrison BJ. Self-sputtering of silver by mono- and polyatomic projectiles: A molecular dynamics investigation. J Chem Phys 2001. [DOI: 10.1063/1.1404982] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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15
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Ingólfsson O, Takeo H, Nonose S. Energy-resolved collision-induced dissociation of Aln+ clusters (n=2–11) in the center of mass energy range from few hundred meV to 10 eV. J Chem Phys 1999. [DOI: 10.1063/1.478320] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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