1
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Deißenbeck F, Wippermann S. Dielectric Properties of Nanoconfined Water from Ab Initio Thermopotentiostat Molecular Dynamics. J Chem Theory Comput 2023; 19:1035-1043. [PMID: 36705611 PMCID: PMC9933428 DOI: 10.1021/acs.jctc.2c00959] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Indexed: 01/28/2023]
Abstract
We discuss how to include our recently proposed thermopotentiostat technique [Deissenbeck et al. Phys. Rev. Lett. 2021, 126, 136803] into any existing ab initio molecular dynamics (AIMD) package. Using thermopotentiostat AIMD simulations in the canonical NVTΦ ensemble at a constant electrode potential, we compute the polarization bound charge and dielectric response of interfacial water from first principles.
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Affiliation(s)
- Florian Deißenbeck
- Max-Planck-Institut
für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Stefan Wippermann
- Max-Planck-Institut
für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
- Philipps-Universität
Marburg, Renthof 5, 35032 Marburg, Germany
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2
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Grandfield K, Micheletti C, Deering J, Arcuri G, Tang T, Langelier B. Atom Probe Tomography for Biomaterials and Biomineralization. Acta Biomater 2022; 148:44-60. [DOI: 10.1016/j.actbio.2022.06.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/18/2022] [Accepted: 06/06/2022] [Indexed: 01/27/2023]
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3
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Qiu L, Morato NM, Huang KH, Cooks RG. Spontaneous Water Radical Cation Oxidation at Double Bonds in Microdroplets. Front Chem 2022; 10:903774. [PMID: 35559217 PMCID: PMC9086510 DOI: 10.3389/fchem.2022.903774] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 04/11/2022] [Indexed: 12/20/2022] Open
Abstract
Spontaneous oxidation of compounds containing diverse X=Y moieties (e.g., sulfonamides, ketones, esters, sulfones) occurs readily in organic-solvent microdroplets. This surprising phenomenon is proposed to be driven by the generation of an intermediate species [M+H2O]+·: a covalent adduct of water radical cation (H2O+·) with the reactant molecule (M). The adduct is observed in the positive ion mass spectrum while its formation in the interfacial region of the microdroplet (i.e., at the air-droplet interface) is indicated by the strong dependence of the oxidation product formation on the spray distance (which reflects the droplet size and consequently the surface-to-volume ratio) and the solvent composition. Importantly, based on the screening of a ca. 21,000-compound library and the detailed consideration of six functional groups, the formation of a molecular adduct with the water radical cation is a significant route to ionization in positive ion mode electrospray, where it is favored in those compounds with X=Y moieties which lack basic groups. A set of model monofunctional systems was studied and in one case, benzyl benzoate, evidence was found for oxidation driven by hydroxyl radical adduct formation followed by protonation in addition to the dominant water radical cation addition process. Significant implications of molecular ionization by water radical cations for oxidation processes in atmospheric aerosols, analytical mass spectrometry and small-scale synthesis are noted.
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4
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Stender P, Gault B, Schwarz TM, Woods EV, Kim SH, Ott J, Stephenson LT, Schmitz G, Freysoldt C, Kästner J, El-Zoka AA. Status and Direction of Atom Probe Analysis of Frozen Liquids. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2022; 28:1-18. [PMID: 35039105 DOI: 10.1017/s1431927621013994] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Imaging of liquids and cryogenic biological materials by electron microscopy has been recently enabled by innovative approaches for specimen preparation and the fast development of optimized instruments for cryo-enabled electron microscopy (cryo-EM). Yet, cryo-EM typically lacks advanced analytical capabilities, in particular for light elements. With the development of protocols for frozen wet specimen preparation, atom probe tomography (APT) could advantageously complement insights gained by cryo-EM. Here, we report on different approaches that have been recently proposed to enable the analysis of relatively large volumes of frozen liquids from either a flat substrate or the fractured surface of a wire. Both allowed for analyzing water ice layers which are several micrometers thick consisting of pure water, pure heavy water, and aqueous solutions. We discuss the merits of both approaches and prospects for further developments in this area. Preliminary results raise numerous questions, in part concerning the physics underpinning field evaporation. We discuss these aspects and lay out some of the challenges regarding the APT analysis of frozen liquids.
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Affiliation(s)
- Patrick Stender
- Institute of Materials Science, Chair of Materials Physics, University of Stuttgart, Heisenbergstrasse 3, 70569Stuttgart, Germany
| | - Baptiste Gault
- Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
- Department of Materials, Royal School of Mines, Imperial College London, London, UK
| | - Tim M Schwarz
- Institute of Materials Science, Chair of Materials Physics, University of Stuttgart, Heisenbergstrasse 3, 70569Stuttgart, Germany
| | - Eric V Woods
- Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
| | - Se-Ho Kim
- Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
| | - Jonas Ott
- Institute of Materials Science, Chair of Materials Physics, University of Stuttgart, Heisenbergstrasse 3, 70569Stuttgart, Germany
| | | | - Guido Schmitz
- Institute of Materials Science, Chair of Materials Physics, University of Stuttgart, Heisenbergstrasse 3, 70569Stuttgart, Germany
| | | | - Johannes Kästner
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569Stuttgart, Germany
| | - Ayman A El-Zoka
- Institute of Materials Science, Chair of Materials Physics, University of Stuttgart, Heisenbergstrasse 3, 70569Stuttgart, Germany
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5
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Hao H, Leven I, Head-Gordon T. Can electric fields drive chemistry for an aqueous microdroplet? Nat Commun 2022; 13:280. [PMID: 35022410 PMCID: PMC8755715 DOI: 10.1038/s41467-021-27941-x] [Citation(s) in RCA: 101] [Impact Index Per Article: 50.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 12/14/2021] [Indexed: 11/20/2022] Open
Abstract
Reaction rates of common organic reactions have been reported to increase by one to six orders of magnitude in aqueous microdroplets compared to bulk solution, but the reasons for the rate acceleration are poorly understood. Using a coarse-grained electron model that describes structural organization and electron densities for water droplets without the expense of ab initio methods, we investigate the electric field distributions at the air-water interface to understand the origin of surface reactivity. We find that electric field alignments along free O-H bonds at the surface are ~16 MV/cm larger on average than that found for O-H bonds in the interior of the water droplet. Furthermore, electric field distributions can be an order of magnitude larger than the average due to non-linear coupling of intramolecular solvent polarization with intermolecular solvent modes which may contribute to even greater surface reactivity for weakening or breaking chemical bonds at the droplet surface.
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Affiliation(s)
- Hongxia Hao
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA, 94720, USA
- Pitzer Center for Theoretical Chemistry, University of California, Berkeley, CA, 94720, USA
- Departments of Chemistry, University of California, Berkeley, CA, 94720, USA
| | - Itai Leven
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA, 94720, USA
- Pitzer Center for Theoretical Chemistry, University of California, Berkeley, CA, 94720, USA
- Departments of Chemistry, University of California, Berkeley, CA, 94720, USA
| | - Teresa Head-Gordon
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA, 94720, USA.
- Pitzer Center for Theoretical Chemistry, University of California, Berkeley, CA, 94720, USA.
- Departments of Chemistry, University of California, Berkeley, CA, 94720, USA.
- Departments of Bioengineering, University of California, Berkeley, CA, 94720, USA.
- Departments of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA.
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6
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Gault B, Klaes B, Morgado FF, Freysoldt C, Li Y, De Geuser F, Stephenson LT, Vurpillot F. Reflections on the Spatial Performance of Atom Probe Tomography in the Analysis of Atomic Neighborhoods. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2021; 28:1-11. [PMID: 34666868 DOI: 10.1017/s1431927621012952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Atom probe tomography (APT) is often introduced as providing “atomic-scale” mapping of the composition of materials and as such is often exploited to analyze atomic neighborhoods within a material. Yet quantifying the actual spatial performance of the technique in a general case remains challenging, as it depends on the material system being investigated as well as on the specimen's geometry. Here, by using comparisons with field-ion microscopy experiments, field-ion imaging and field evaporation simulations, we provide the basis for a critical reflection on the spatial performance of APT in the analysis of pure metals, low alloyed systems and concentrated solid solutions (i.e., akin to high-entropy alloys). The spatial resolution imposes strong limitations on the possible interpretation of measured atomic neighborhoods, and directional neighborhood analyses restricted to the depth are expected to be more robust. We hope this work gets the community to reflect on its practices, in the same way, it got us to reflect on our work.
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Affiliation(s)
- Baptiste Gault
- Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, Düsseldorf40237, Germany
- Department of Materials, Royal School of Mines, Imperial College, Prince Consort Road, LondonSW7 2BP, UK
| | - Benjamin Klaes
- Groupe Physique des Matériaux, Université de Rouen, Saint Etienne du Rouvray, Normandie76800, France
| | - Felipe F Morgado
- Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, Düsseldorf40237, Germany
| | - Christoph Freysoldt
- Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, Düsseldorf40237, Germany
| | - Yue Li
- Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, Düsseldorf40237, Germany
| | - Frederic De Geuser
- Université Grenoble Alpes, CNRS, Grenoble INP, SIMAP, Grenoble38000, France
| | - Leigh T Stephenson
- Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, Düsseldorf40237, Germany
| | - François Vurpillot
- Groupe Physique des Matériaux, Université de Rouen, Saint Etienne du Rouvray, Normandie76800, France
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7
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Ahmadian A, Scheiber D, Zhou X, Gault B, Liebscher CH, Romaner L, Dehm G. Aluminum depletion induced by co-segregation of carbon and boron in a bcc-iron grain boundary. Nat Commun 2021; 12:6008. [PMID: 34650043 PMCID: PMC8516984 DOI: 10.1038/s41467-021-26197-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 09/13/2021] [Indexed: 12/02/2022] Open
Abstract
The local variation of grain boundary atomic structure and chemistry caused by segregation of impurities influences the macroscopic properties of polycrystalline materials. Here, the effect of co-segregation of carbon and boron on the depletion of aluminum at a Σ5 (3 1 0 )[0 0 1] tilt grain boundary in a α - Fe-4 at%Al bicrystal is studied by combining atomic resolution scanning transmission electron microscopy, atom probe tomography and density functional theory calculations. The atomic grain boundary structural units mostly resemble kite-type motifs and the structure appears disrupted by atomic scale defects. Atom probe tomography reveals that carbon and boron impurities are co-segregating to the grain boundary reaching levels of >1.5 at%, whereas aluminum is locally depleted by approx. 2 at.%. First-principles calculations indicate that carbon and boron exhibit the strongest segregation tendency and their repulsive interaction with aluminum promotes its depletion from the grain boundary. It is also predicted that substitutional segregation of boron atoms may contribute to local distortions of the kite-type structural units. These results suggest that the co-segregation and interaction of interstitial impurities with substitutional solutes strongly influences grain boundary composition and with this the properties of the interface.
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Affiliation(s)
- A Ahmadian
- Max-Planck-Institut fuer Eisenforschung GmbH, Düsseldorf, Germany.
| | - D Scheiber
- Materials Center Leoben GmbH, Leoben, Austria
| | - X Zhou
- Max-Planck-Institut fuer Eisenforschung GmbH, Düsseldorf, Germany
| | - B Gault
- Max-Planck-Institut fuer Eisenforschung GmbH, Düsseldorf, Germany
- Department of Materials, Royal School of Mines, Imperial College London, London, UK
| | - C H Liebscher
- Max-Planck-Institut fuer Eisenforschung GmbH, Düsseldorf, Germany
| | - L Romaner
- Materials Center Leoben GmbH, Leoben, Austria
- Montanuniversität Leoben, Leoben, Austria
| | - G Dehm
- Max-Planck-Institut fuer Eisenforschung GmbH, Düsseldorf, Germany
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8
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Kühbach M, Kasemer M, Gault B, Breen A. Open and strong-scaling tools for atom-probe crystallography: high-throughput methods for indexing crystal structure and orientation. J Appl Crystallogr 2021; 54:1490-1508. [PMID: 34667452 PMCID: PMC8493626 DOI: 10.1107/s1600576721008578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 08/17/2021] [Indexed: 11/10/2022] Open
Abstract
Volumetric crystal structure indexing and orientation mapping are key data processing steps for virtually any quantitative study of spatial correlations between the local chemical composition features and the microstructure of a material. For electron and X-ray diffraction methods it is possible to develop indexing tools which compare measured and analytically computed patterns to decode the structure and relative orientation within local regions of interest. Consequently, a number of numerically efficient and automated software tools exist to solve the above characterization tasks. For atom-probe tomography (APT) experiments, however, the strategy of making comparisons between measured and analytically computed patterns is less robust because many APT data sets contain substantial noise. Given that sufficiently general predictive models for such noise remain elusive, crystallography tools for APT face several limitations: their robustness to noise is limited, and therefore so too is their capability to identify and distinguish different crystal structures and orientations. In addition, the tools are sequential and demand substantial manual interaction. In combination, this makes robust uncertainty quantification with automated high-throughput studies of the latent crystallographic information a difficult task with APT data. To improve the situation, the existing methods are reviewed and how they link to the methods currently used by the electron and X-ray diffraction communities is discussed. As a result of this, some of the APT methods are modified to yield more robust descriptors of the atomic arrangement. Also reported is how this enables the development of an open-source software tool for strong scaling and automated identification of a crystal structure, and the mapping of crystal orientation in nanocrystalline APT data sets with multiple phases.
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Affiliation(s)
- Markus Kühbach
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Strasse 1, D-40237 Düsseldorf, Germany
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Matthew Kasemer
- Department of Mechanical Engineering, University of Alabama, Tuscaloosa, AL 35487, USA
| | - Baptiste Gault
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Strasse 1, D-40237 Düsseldorf, Germany
- Department of Materials, Imperial College London, Royal School of Mines, London, United Kingdom
| | - Andrew Breen
- University of Sydney, Australian Centre for Microscopy and Microanalysis, NSW 2006 Sydney, Australia
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9
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Deißenbeck F, Freysoldt C, Todorova M, Neugebauer J, Wippermann S. Dielectric Properties of Nanoconfined Water: A Canonical Thermopotentiostat Approach. PHYSICAL REVIEW LETTERS 2021; 126:136803. [PMID: 33861101 DOI: 10.1103/physrevlett.126.136803] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 08/14/2020] [Accepted: 02/26/2021] [Indexed: 06/12/2023]
Abstract
We introduce a novel approach to sample the canonical ensemble at constant temperature and applied electric potential. Our approach can be straightforwardly implemented into any density-functional theory code. Using thermopotentiostat molecular dynamics simulations allows us to compute the dielectric constant of nanoconfined water without any assumptions for the dielectric volume. Compared to the commonly used approach of calculating dielectric properties from polarization fluctuations, our thermopotentiostat technique reduces the required computational time by 2 orders of magnitude.
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Affiliation(s)
- F Deißenbeck
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237Düsseldorf, Germany
| | - C Freysoldt
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237Düsseldorf, Germany
| | - M Todorova
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237Düsseldorf, Germany
| | - J Neugebauer
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237Düsseldorf, Germany
| | - S Wippermann
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237Düsseldorf, Germany
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10
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Ohnuma T. First-Principles Calculation of the Evaporation Field and Roll-up Effect of M (M = Fe, Cu, Si, and Mn) on the Fe (001) and Fe Step Structure. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2021; 28:1-7. [PMID: 33691820 DOI: 10.1017/s1431927621000155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
First-principles calculations were performed on the evaporation field of Fe, Cu, Mn, and Si in Fe (001) and on the evaporation field and roll-up effect of Fe, Cu, and Mn in the Fe (001) step structure. The larger the evaporation barrier energy tendency, at an electric field of 0 V/nm (absorption energy), the larger was the evaporation field. Electric field evaporation calculation results indicate that the order in which the electric field is easily evaporated is Mn > Cu > Fe > Si. The tendency that Mn and Cu evaporate more easily than does Fe and that the evaporation of Si is less probable is consistent with the experiment of a dilute element in steel. In the Fe (001) step structure, when the electric field is low, the roll-up effect where the evaporated atoms move on the step is large, and when the electric field is large, the roll-up effect is small. The roll-up effect of Cu was almost the same as that of Fe, and the roll-up effect of Mn was small because the chemical bond between Mn and Fe was weak.
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Affiliation(s)
- Toshiharu Ohnuma
- Materials Science Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), 2-6-1 Nagasaka, Yokosuka-shi, Kanagawa-ken240-0196, Japan
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11
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Gault B, Chiaramonti A, Cojocaru-Mirédin O, Stender P, Dubosq R, Freysoldt C, Makineni SK, Li T, Moody M, Cairney JM. Atom probe tomography. NATURE REVIEWS. METHODS PRIMERS 2021; 1:10.1038/s43586-021-00047-w. [PMID: 37719173 PMCID: PMC10502706 DOI: 10.1038/s43586-021-00047-w] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/01/2021] [Indexed: 09/19/2023]
Abstract
Atom probe tomography (APT) provides three-dimensional compositional mapping with sub-nanometre resolution. The sensitivity of APT is in the range of parts per million for all elements, including light elements such as hydrogen, carbon or lithium, enabling unique insights into the composition of performance-enhancing or lifetime-limiting microstructural features and making APT ideally suited to complement electron-based or X-ray-based microscopies and spectroscopies. Here, we provide an introductory overview of APT ranging from its inception as an evolution of field ion microscopy to the most recent developments in specimen preparation, including for nanomaterials. We touch on data reconstruction, analysis and various applications, including in the geosciences and the burgeoning biological sciences. We review the underpinnings of APT performance and discuss both strengths and limitations of APT, including how the community can improve on current shortcomings. Finally, we look forwards to true atomic-scale tomography with the ability to measure the isotopic identity and spatial coordinates of every atom in an ever wider range of materials through new specimen preparation routes, novel laser pulsing and detector technologies, and full interoperability with complementary microscopy techniques.
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Affiliation(s)
- Baptiste Gault
- Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
- Department of Materials, Royal School of Mines, Imperial College, London, UK
| | - Ann Chiaramonti
- National Institute of Standards and Technology, Applied Chemicals and Materials Division, Boulder, CO, USA
| | | | - Patrick Stender
- Institute of Materials Science, University of Stuttgart, Stuttgart, Germany
| | - Renelle Dubosq
- Department of Earth and Environmental Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | | | | | - Tong Li
- Institute for Materials, Ruhr-Universität Bochum, Bochum, Germany
| | - Michael Moody
- Department of Materials, University of Oxford, Oxford, UK
| | - Julie M. Cairney
- Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales, Australia
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, New South Wales, Australia
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12
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Dietrich CA, Schuldt R, Born D, Solodenko H, Schmitz G, Kästner J. Evaporation and Fragmentation of Organic Molecules in Strong Electric Fields Simulated with DFT. J Phys Chem A 2020; 124:8633-8642. [PMID: 32946231 DOI: 10.1021/acs.jpca.0c06887] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Atom probe tomography allows us to measure the three-dimensional composition of materials with up to atomic resolution by evaporating the material using high electric fields. Initially developed for metals, it is increasingly used for covalently bound structures. To aid the interpretation of the obtained fragmentation pattern, we modeled the fragmentation and desorption of self-assembled monolayers of thiolate molecules on a gold surface in strong electrostatic fields using density functional theory. We used a cluster model and a periodic model of amino-undecanethiolate, NH2(CH2)11S, and fluoro-decanethiolate, CF3(CF2)7(CH2)2S. In the former molecule, the fragment CH2NH2+ was found to evaporate at fields of 5.4-7.7 V/nm. It was followed by different hydrocarbon fragments. Fluoro-decanethiolate evaporates CF3+ at fields of 5.7-6.7 V/nm in the cluster model and at 15.4-23.1 V/nm in the periodic model, followed by CF2+ and C2F42+. Detailed analysis of the electronic structure during the evaporation process revealed a stepwise accumulation of the charge in the head groups exposed to the strongest fields, followed by dissociation of covalent bonds. These observations will facilitate the analysis of atom probe experiments of covalently bound structures.
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Affiliation(s)
- Carolin A Dietrich
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Robin Schuldt
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Daniel Born
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Helena Solodenko
- Institute for Materials Science, University of Stuttgart, Heisenbergstr. 3, 70569 Stuttgart, Germany
| | - Guido Schmitz
- Institute for Materials Science, University of Stuttgart, Heisenbergstr. 3, 70569 Stuttgart, Germany
| | - Johannes Kästner
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
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13
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Hatzoglou C, Rouland S, Radiguet B, Etienne A, Costa GD, Sauvage X, Pareige P, Vurpillot F. Preferential Evaporation in Atom Probe Tomography: An Analytical Approach. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2020; 26:689-698. [PMID: 32627726 DOI: 10.1017/s1431927620001749] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Atom probe tomography (APT) analysis conditions play a major role in the composition measurement accuracy. Preferential evaporation (PE), which significantly biases the apparent composition, more than other well-known phenomena in APT, is strongly connected to those analysis conditions. One way to optimize them, in order to have the most accurate measurement, is therefore to be able to predict and then to estimate their influence on the apparent composition. An analytical model is proposed to quantify the PE. This model is applied to three different alloys such as NiCu, FeCrNi, and FeCu. The model explains not only the analysis temperature dependence, as in an already existing model, but also the dependence to the pulse fraction and the pulse frequency. Moreover, the model can also provide an energetic constant directly linked to the energy barrier required to field evaporate atom from the sample surface.
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Affiliation(s)
- Constantinos Hatzoglou
- Normandie Université, UNIROUEN, INSA Rouen, CNRS, Groupe de Physique des Matériaux, 76000Rouen, France
- Department of Materials Science and Engineering, NTNU, Norwegian University of Science and Technology, Trondheim7491, Norway
| | - Solène Rouland
- Normandie Université, UNIROUEN, INSA Rouen, CNRS, Groupe de Physique des Matériaux, 76000Rouen, France
| | - Bertrand Radiguet
- Normandie Université, UNIROUEN, INSA Rouen, CNRS, Groupe de Physique des Matériaux, 76000Rouen, France
| | - Auriane Etienne
- Normandie Université, UNIROUEN, INSA Rouen, CNRS, Groupe de Physique des Matériaux, 76000Rouen, France
| | - Gérald Da Costa
- Normandie Université, UNIROUEN, INSA Rouen, CNRS, Groupe de Physique des Matériaux, 76000Rouen, France
| | - Xavier Sauvage
- Normandie Université, UNIROUEN, INSA Rouen, CNRS, Groupe de Physique des Matériaux, 76000Rouen, France
| | - Philippe Pareige
- Normandie Université, UNIROUEN, INSA Rouen, CNRS, Groupe de Physique des Matériaux, 76000Rouen, France
| | - François Vurpillot
- Normandie Université, UNIROUEN, INSA Rouen, CNRS, Groupe de Physique des Matériaux, 76000Rouen, France
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