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Segreto N, Schwarz TM, Dietrich CA, Stender P, Schuldt R, Schmitz G, Kästner J. Understanding the Underlying Field Evaporation Mechanism of Pure Water Tips in High Electrical Fields. J Phys Chem A 2022; 126:5663-5671. [PMID: 35972399 DOI: 10.1021/acs.jpca.2c04163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We investigated the field evaporation process of frozen water in atom probe tomography (APT) by density functional simulations. In previous experiments, a strong tailing effect was observed for peaks caused by the molecular structure (H2O)nH+, in contrast to other peaks. In purely field-induced and thermally assisted evaporation simulations, we found that chains of protonated water molecules were pulled out of the dielectric surface by up to 6 Å, which are stable over a wide range of field strengths. Therefore, the resulting water clusters experience only part of the acceleration after evaporation compared to molecules evaporating directly from the surface and, thus, exhibit an energy deficit, which explains the tailing effect. Our simulations provide new insight into the complex evaporation behavior of water in high electrical fields and reveal possibilities for adapting the existing reconstruction algorithms.
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Affiliation(s)
- Nico Segreto
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Tim M Schwarz
- Institute for Materials Science, Chair of Materials Physics, University of Stuttgart, Heisenbergstraße 3, 70569 Stuttgart, Germany
| | - Carolin A Dietrich
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Patrick Stender
- Institute for Materials Science, Chair of Materials Physics, University of Stuttgart, Heisenbergstraße 3, 70569 Stuttgart, Germany
| | - Robin Schuldt
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Guido Schmitz
- Institute for Materials Science, Chair of Materials Physics, University of Stuttgart, Heisenbergstraße 3, 70569 Stuttgart, Germany
| | - Johannes Kästner
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
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2
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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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3
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Bingham JT, Proudian AP, Vyas S, Zimmerman JD. Understanding Fragmentation of Organic Small Molecules in Atom Probe Tomography. J Phys Chem Lett 2021; 12:10437-10443. [PMID: 34672587 DOI: 10.1021/acs.jpclett.1c02277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In atom probe tomography of molecular organic materials, field ionization of either entire molecules or molecular fragments can occur, but the mechanism governing this behavior was not previously understood. This work explains when a doubly ionized small molecule organic material is expected to undergo fragmentation. We find that multiple detection events arising from post-ionization fragmentation of a parent molecular dication into two daughter ions is well explained by the free energy and geometries of the molecules computed using density functional theory. Of the systems studied, exergonic free energies for formation of the daughter ions, smaller activation energies for dissociation, and increases in bond length are all found to be quantitative predictors for ion fragmentation. This work expands the applicability of atom probe tomography to organic materials by increasing the fundamental understanding of processes occurring during this analysis technique.
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Affiliation(s)
- Jacob T Bingham
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Andrew P Proudian
- Department of Physics, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Shubham Vyas
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Jeramy D Zimmerman
- Department of Physics, Colorado School of Mines, Golden, Colorado 80401, United States
- Materials Science Program, Colorado School of Mines, Golden, Colorado 80401, United States
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Solodenko H, Stender P, Schmitz G. Atom Probe Study of 1-Octadecanethiol Self-Assembled Monolayers on Platinum (111) and (200) Surfaces. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2021; 28:1-10. [PMID: 34490841 DOI: 10.1017/s1431927621012654] [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 measurements of self-assembled monolayers of 1-octadecanethiol on platinum tips were performed and their fragmentation behavior under the influence of different laser powers was investigated. The carbon backbone evaporates in the form of small hydrocarbon fragments consisting of one to four carbon atoms, while sulfur evaporates exclusively as single ions. The carbon molecules evaporate at very low fields of 5.9 V/nm, while S requires a considerably higher evaporation field of 23.4 V/nm. With increasing laser power, a weak, but noticeable trend toward larger fragment sizes is observed. No hydrocarbon fragments containing S are detected, indicating that a strong S–Pt bond has formed. The observed surface coverage of S fits well with literature values and is higher for (111)-oriented samples than for (200).
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Affiliation(s)
- Helena Solodenko
- Institute for Materials Science, Chair of Materials Physics, University of Stuttgart, Heisenbergstr. 3, 70569Stuttgart, Germany
| | - Patrick Stender
- Institute for Materials Science, Chair of Materials Physics, University of Stuttgart, Heisenbergstr. 3, 70569Stuttgart, Germany
| | - Guido Schmitz
- Institute for Materials Science, Chair of Materials Physics, University of Stuttgart, Heisenbergstr. 3, 70569Stuttgart, Germany
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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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El-Zoka AA, Kim SH, Deville S, Newman RC, Stephenson LT, Gault B. Enabling near-atomic-scale analysis of frozen water. SCIENCE ADVANCES 2020; 6:6/49/eabd6324. [PMID: 33277259 PMCID: PMC7821902 DOI: 10.1126/sciadv.abd6324] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 10/21/2020] [Indexed: 05/04/2023]
Abstract
Transmission electron microscopy went through a revolution enabling routine cryo-imaging of biological and (bio)chemical systems, in liquid form. Yet, these approaches typically lack advanced analytical capabilities. Here, we used atom probe tomography to analyze frozen liquids in three dimensions with subnanometer resolution. We introduce a specimen preparation strategy using nanoporous gold. We report data on 2- to 3-μm-thick layers of ice formed from both high-purity deuterated water and a solution of 50 mM NaCl in high-purity deuterated water. The analysis of the gold-ice interface reveals a substantial increase in the solute concentrations across the interface. We explore a range of experimental parameters to show that atom probe analyses of bulk aqueous specimens come with their own challenges and discuss physical processes that produce the observed phenomena. Our study demonstrates the viability of using frozen water as a carrier for near-atomic-scale analysis of objects in solution by atom probe tomography.
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Affiliation(s)
- A A El-Zoka
- Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany.
| | - S-H Kim
- Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
| | - S Deville
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, 69622 Villeurbanne, France
| | - R C Newman
- Department of Chemical Engineering & Applied Chemistry, University of Toronto, Toronto, Canada
| | - L T Stephenson
- Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
| | - B Gault
- Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany.
- Department of Materials, Royal School of Mines, Imperial College London, London, UK
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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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