51
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Gazder AA, Elkhodary KI, Nancarrow MJ, Saleh AA. Transmission Kikuchi diffraction versus electron back-scattering diffraction: A case study on an electron transparent cross-section of TWIP steel. Micron 2017; 103:53-63. [DOI: 10.1016/j.micron.2017.09.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 09/20/2017] [Accepted: 09/20/2017] [Indexed: 12/01/2022]
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52
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Brodu E, Bouzy E. Depth Resolution Dependence on Sample Thickness and Incident Energy in On-Axis Transmission Kikuchi Diffraction in Scanning Electron Microscope (SEM). MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2017; 23:1096-1106. [PMID: 29282164 DOI: 10.1017/s1431927617012697] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Transmission Kikuchi diffraction is an emerging technique aimed at producing orientation maps of the structure of materials with a nanometric lateral resolution. This study investigates experimentally the depth resolution of the on-axis configuration, via a twinned silicon bi-crystal sample specifically designed and fabricated. The measured depth resolution varies from 30 to 65 nm in the range 10-30 keV, with a close to linear dependence with incident energy and no dependence with the total sample thickness. The depth resolution is explained in terms of two mechanisms acting concomitantly: generation of Kikuchi diffraction all along the thickness of the sample, associated with continuous absorption on the way out. A model based on the electron mean free path is used to account for the dependence with incident energy of the depth resolution. In addition, based on the results in silicon, the use of the mean absorption coefficient is proposed to predict the depth resolution for any atomic number and incident energy.
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Affiliation(s)
- Etienne Brodu
- 1Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3),UMR CNRS 7239,Université de Lorraine,57045 Metz,France
| | - Emmanuel Bouzy
- 1Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3),UMR CNRS 7239,Université de Lorraine,57045 Metz,France
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53
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Singh S, Ram F, De Graef M. Application of forward models to crystal orientation refinement. J Appl Crystallogr 2017. [DOI: 10.1107/s1600576717014200] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Two approaches are proposed for the refinement of electron diffraction pattern indexing. The approaches require two basic ingredients: an accurate physics-based forward model and an algorithm to search the local orientation neighborhood. Forward models for electron backscatter diffraction (EBSD) and electron channeling pattern (ECP) modalities are coupled with either a multi-resolution brute-force search algorithm or a bound optimization by quadratic approximation algorithm. The efficacy of the methods is evaluated for varying levels of error in the pattern projection center. The EBSD modality shows an orientation improvement when the projection center error is within ±1% of the full detector width, whereas the ECP modality shows improvement up to a ±5% error. The algorithms are applied to an experimental EBSD scan for partially recrystallized 90/10 brass; the results show that the refinement is necessary to remove the artifacts introduced by the discrete sampling nature of the dictionary indexing method. Finally, a pattern center correction factor is derived for orientations obtained from dictionary indexing for large-area EBSD scans.
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54
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Alekseeva S, Fanta ABDS, Iandolo B, Antosiewicz TJ, Nugroho FAA, Wagner JB, Burrows A, Zhdanov VP, Langhammer C. Grain boundary mediated hydriding phase transformations in individual polycrystalline metal nanoparticles. Nat Commun 2017; 8:1084. [PMID: 29057929 PMCID: PMC5651804 DOI: 10.1038/s41467-017-00879-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 08/02/2017] [Indexed: 11/09/2022] Open
Abstract
Grain boundaries separate crystallites in solids and influence material properties, as widely documented for bulk materials. In nanomaterials, however, investigations of grain boundaries are very challenging and just beginning. Here, we report the systematic mapping of the role of grain boundaries in the hydrogenation phase transformation in individual Pd nanoparticles. Employing multichannel single-particle plasmonic nanospectroscopy, we observe large variation in particle-specific hydride-formation pressure, which is absent in hydride decomposition. Transmission Kikuchi diffraction suggests direct correlation between length and type of grain boundaries and hydride-formation pressure. This correlation is consistent with tensile lattice strain induced by hydrogen localized near grain boundaries as the dominant factor controlling the phase transition during hydrogen absorption. In contrast, such correlation is absent for hydride decomposition, suggesting a different phase-transition pathway. In a wider context, our experimental setup represents a powerful platform to unravel microstructure-function correlations at the individual-nanoparticle level.
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Affiliation(s)
- Svetlana Alekseeva
- Department of Physics, Chalmers University of Technology, Göteborg, 412 96, Sweden
| | | | - Beniamino Iandolo
- Center for Electron Nanoscopy, Technical University of Denmark, Fysikvej, 2800 Kgs, Lyngby, Denmark.,Department of Microtechnology and Nanotechnology, Technical University of Denmark, Ørsteds Pl., 2800 Kgs, Lyngby, Denmark
| | - Tomasz J Antosiewicz
- Department of Physics, Chalmers University of Technology, Göteborg, 412 96, Sweden.,Centre of New Technologies, University of Warsaw, Banacha 2c, Warsaw, 02-097, Poland
| | | | - Jakob B Wagner
- Center for Electron Nanoscopy, Technical University of Denmark, Fysikvej, 2800 Kgs, Lyngby, Denmark
| | - Andrew Burrows
- Center for Electron Nanoscopy, Technical University of Denmark, Fysikvej, 2800 Kgs, Lyngby, Denmark
| | - Vladimir P Zhdanov
- Department of Physics, Chalmers University of Technology, Göteborg, 412 96, Sweden.,Boreskov Institute of Catalysis, Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Christoph Langhammer
- Department of Physics, Chalmers University of Technology, Göteborg, 412 96, Sweden.
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55
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Judge CD, Li W, Mayhew C, Buyers A, Bickel GA. ADOPTING TRANSMISSION KIKUCHI DIFFRACTION TO CHARACTERIZE GRAIN STRUCTURE AND TEXTURE OF ZR-2.5NB CANDU PRESSURE TUBES. CNL NUCLEAR REVIEW 2017. [DOI: 10.12943/cnr.2017.00010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Colin David Judge
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
| | - Wenjing Li
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
| | - Clinton Mayhew
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
| | - Andrew Buyers
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
| | - Grant A. Bickel
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
- Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
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56
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Brodu E, Bouzy E, Fundenberger JJ. Diffraction contrast dependence on sample thickness and incident energy in on-axis Transmission Kikuchi Diffraction in SEM. Ultramicroscopy 2017; 181:123-133. [DOI: 10.1016/j.ultramic.2017.04.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 02/17/2017] [Accepted: 04/28/2017] [Indexed: 11/16/2022]
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57
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VALERY A, RAUCH E, CLÉMENT L, LORUT F. Retrieving overlapping crystals information from TEM nano-beam electron diffraction patterns. J Microsc 2017; 268:208-218. [DOI: 10.1111/jmi.12599] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 06/05/2017] [Accepted: 06/06/2017] [Indexed: 11/25/2022]
Affiliation(s)
- A. VALERY
- Physical Characterization group, STMicroelectronics; Crolles France
- SIMaP Laboratory, CNRS, Université Grenoble Alpes; Grenoble France
| | - E.F. RAUCH
- SIMaP Laboratory, CNRS, Université Grenoble Alpes; Grenoble France
| | - L. CLÉMENT
- Physical Characterization group, STMicroelectronics; Crolles France
| | - F. LORUT
- Physical Characterization group, STMicroelectronics; Crolles France
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58
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Shih JW, Kuo KW, Kuo JC, Kuo TY. Effects of accelerating voltage and specimen thickness on the spatial resolution of transmission electron backscatter diffraction in Cu. Ultramicroscopy 2017; 177:43-52. [DOI: 10.1016/j.ultramic.2017.01.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 01/23/2017] [Accepted: 01/29/2017] [Indexed: 10/20/2022]
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59
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De Geuser F, Gault B. Reflections on the Projection of Ions in Atom Probe Tomography. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2017; 23:238-246. [PMID: 28148309 DOI: 10.1017/s1431927616012721] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
There are two main projections used to transform, and reconstruct, field ion micrographs or atom probe tomography data into atomic coordinates at the specimen surface and, subsequently, in three dimensions. In this article, we present a perspective on the strength of the azimuthal equidistant projection in comparison with the more widely used and well-established point projection (or pseudo-stereographic projection), which underpins data reconstruction in most software packages currently in use across the community. After an overview of the reconstruction methodology, we demonstrate that the azimuthal equidistant is more robust with regards to errors on the parameters used to perform the reconstruction and is therefore more likely to yield more accurate tomographic reconstructions.
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Affiliation(s)
| | - Baptiste Gault
- 3Max-Planck Institut für Eisenforschung,Max-Planck-Straße 1,D-40237 Dsseldorf,Germany
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60
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Prosa TJ, Larson DJ. Modern Focused-Ion-Beam-Based Site-Specific Specimen Preparation for Atom Probe Tomography. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2017; 23:194-209. [PMID: 28162119 DOI: 10.1017/s1431927616012642] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Approximately 30 years after the first use of focused ion beam (FIB) instruments to prepare atom probe tomography specimens, this technique has grown to be used by hundreds of researchers around the world. This past decade has seen tremendous advances in atom probe applications, enabled by the continued development of FIB-based specimen preparation methodologies. In this work, we provide a short review of the origin of the FIB method and the standard methods used today for lift-out and sharpening, using the annular milling method as applied to atom probe tomography specimens. Key steps for enabling correlative analysis with transmission electron-beam backscatter diffraction, transmission electron microscopy, and atom probe tomography are presented, and strategies for preparing specimens for modern microelectronic device structures are reviewed and discussed in detail. Examples are used for discussion of the steps for each of these methods. We conclude with examples of the challenges presented by complex topologies such as nanowires, nanoparticles, and organic materials.
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Affiliation(s)
- Ty J Prosa
- Cameca Instruments Inc.,5500 Nobel Drive,Madison,WI 53711,USA
| | - David J Larson
- Cameca Instruments Inc.,5500 Nobel Drive,Madison,WI 53711,USA
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61
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Proust G, Trimby P, Piazolo S, Retraint D. Characterization of Ultra-fine Grained and Nanocrystalline Materials Using Transmission Kikuchi Diffraction. J Vis Exp 2017. [PMID: 28447998 PMCID: PMC5564465 DOI: 10.3791/55506] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
One of the challenges in microstructure analysis nowadays resides in the reliable and accurate characterization of ultra-fine grained (UFG) and nanocrystalline materials. The traditional techniques associated with scanning electron microscopy (SEM), such as electron backscatter diffraction (EBSD), do not possess the required spatial resolution due to the large interaction volume between the electrons from the beam and the atoms of the material. Transmission electron microscopy (TEM) has the required spatial resolution. However, due to a lack of automation in the analysis system, the rate of data acquisition is slow which limits the area of the specimen that can be characterized. This paper presents a new characterization technique, Transmission Kikuchi Diffraction (TKD), which enables the analysis of the microstructure of UFG and nanocrystalline materials using an SEM equipped with a standard EBSD system. The spatial resolution of this technique can reach 2 nm. This technique can be applied to a large range of materials that would be difficult to analyze using traditional EBSD. After presenting the experimental set up and describing the different steps necessary to realize a TKD analysis, examples of its use on metal alloys and minerals are shown to illustrate the resolution of the technique and its flexibility in term of material to be characterized.
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Affiliation(s)
| | - Patrick Trimby
- Australian Centre for Microscopy and Microanalysis, The University of Sydney
| | - Sandra Piazolo
- Department of Earth and Planetary Sciences, Macquarie University
| | - Delphine Retraint
- Charles Delaunay Institute, LASMIS, UMR STMR CNRS 6281, University of Technology of Troyes
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62
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Breen AJ, Babinsky K, Day AC, Eder K, Oakman CJ, Trimby PW, Primig S, Cairney JM, Ringer SP. Correlating Atom Probe Crystallographic Measurements with Transmission Kikuchi Diffraction Data. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2017; 23:279-290. [PMID: 28288697 DOI: 10.1017/s1431927616012605] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Correlative microscopy approaches offer synergistic solutions to many research problems. One such combination, that has been studied in limited detail, is the use of atom probe tomography (APT) and transmission Kikuchi diffraction (TKD) on the same tip specimen. By combining these two powerful microscopy techniques, the microstructure of important engineering alloys can be studied in greater detail. For the first time, the accuracy of crystallographic measurements made using APT will be independently verified using TKD. Experimental data from two atom probe tips, one a nanocrystalline Al-0.5Ag alloy specimen collected on a straight flight-path atom probe and the other a high purity Mo specimen collected on a reflectron-fitted instrument, will be compared. We find that the average minimum misorientation angle, calculated from calibrated atom probe reconstructions with two different pole combinations, deviate 0.7° and 1.4°, respectively, from the TKD results. The type of atom probe and experimental conditions appear to have some impact on this accuracy and the reconstruction and measurement procedures are likely to contribute further to degradation in angular resolution. The challenges and implications of this correlative approach will also be discussed.
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Affiliation(s)
- Andrew J Breen
- 1Australian Centre for Microscopy and Microanalysis,The University of Sydney,Sydney,NSW 2006,Australia
| | - Katharina Babinsky
- 3Department of Physical Metallurgy and Materials Testing,Montanuniversität Leoben,Franz-Josef Straße 18,8700 Leoben,Austria
| | - Alec C Day
- 1Australian Centre for Microscopy and Microanalysis,The University of Sydney,Sydney,NSW 2006,Australia
| | - K Eder
- 1Australian Centre for Microscopy and Microanalysis,The University of Sydney,Sydney,NSW 2006,Australia
| | - Connor J Oakman
- 1Australian Centre for Microscopy and Microanalysis,The University of Sydney,Sydney,NSW 2006,Australia
| | - Patrick W Trimby
- 1Australian Centre for Microscopy and Microanalysis,The University of Sydney,Sydney,NSW 2006,Australia
| | - Sophie Primig
- 4School of Materials Science and Engineering,The University of New South Wales,Sydney,NSW 2052,Australia
| | - Julie M Cairney
- 1Australian Centre for Microscopy and Microanalysis,The University of Sydney,Sydney,NSW 2006,Australia
| | - Simon P Ringer
- 1Australian Centre for Microscopy and Microanalysis,The University of Sydney,Sydney,NSW 2006,Australia
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63
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La Fontaine A, Piazolo S, Trimby P, Yang L, Cairney JM. Laser-Assisted Atom Probe Tomography of Deformed Minerals: A Zircon Case Study. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2017; 23:404-413. [PMID: 28134066 DOI: 10.1017/s1431927616012745] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The application of atom probe tomography to the study of minerals is a rapidly growing area. Picosecond-pulsed, ultraviolet laser (UV-355 nm) assisted atom probe tomography has been used to analyze trace element mobility within dislocations and low-angle boundaries in plastically deformed specimens of the nonconductive mineral zircon (ZrSiO4), a key material to date the earth's geological events. Here we discuss important experimental aspects inherent in the atom probe tomography investigation of this important mineral, providing insights into the challenges in atom probe tomography characterization of minerals as a whole. We studied the influence of atom probe tomography analysis parameters on features of the mass spectra, such as the thermal tail, as well as the overall data quality. Three zircon samples with different uranium and lead content were analyzed, and particular attention was paid to ion identification in the mass spectra and detection limits of the key trace elements, lead and uranium. We also discuss the correlative use of electron backscattered diffraction in a scanning electron microscope to map the deformation in the zircon grains, and the combined use of transmission Kikuchi diffraction and focused ion beam sample preparation to assist preparation of the final atom probe tip.
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Affiliation(s)
- Alexandre La Fontaine
- 1School of Aerospace, Mechanical, Mechatronic Engineering,The University of Sydney,NSW 2006,Australia
| | - Sandra Piazolo
- 3Department of Earth and Planetary Science,Macquarie University,NSW 2109,Australia
| | - Patrick Trimby
- 2Australian Centre for Microscopy and Microanalysis,The University of Sydney,NSW 2006,Australia
| | - Limei Yang
- 2Australian Centre for Microscopy and Microanalysis,The University of Sydney,NSW 2006,Australia
| | - Julie M Cairney
- 1School of Aerospace, Mechanical, Mechatronic Engineering,The University of Sydney,NSW 2006,Australia
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64
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YUAN H, BRODU E, CHEN C, BOUZY E, FUNDENBERGER JJ, TOTH L. On-axis versus off-axis Transmission Kikuchi Diffraction technique: application to the characterisation of severe plastic deformation-induced ultrafine-grained microstructures. J Microsc 2017; 267:70-80. [DOI: 10.1111/jmi.12548] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 02/08/2017] [Accepted: 02/12/2017] [Indexed: 12/01/2022]
Affiliation(s)
- H. YUAN
- Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3); Université de Lorraine; Metz France
- Laboratory of Excellence on Design of Alloy Metals for low-Mass Structures (DAMAS); University of Lorraine; Metz France
| | - E. BRODU
- Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3); Université de Lorraine; Metz France
- Laboratory of Excellence on Design of Alloy Metals for low-Mass Structures (DAMAS); University of Lorraine; Metz France
| | - C. CHEN
- Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3); Université de Lorraine; Metz France
- Laboratory of Excellence on Design of Alloy Metals for low-Mass Structures (DAMAS); University of Lorraine; Metz France
| | - E. BOUZY
- Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3); Université de Lorraine; Metz France
- Laboratory of Excellence on Design of Alloy Metals for low-Mass Structures (DAMAS); University of Lorraine; Metz France
| | - J-J. FUNDENBERGER
- Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3); Université de Lorraine; Metz France
- Laboratory of Excellence on Design of Alloy Metals for low-Mass Structures (DAMAS); University of Lorraine; Metz France
| | - L.S. TOTH
- Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3); Université de Lorraine; Metz France
- Laboratory of Excellence on Design of Alloy Metals for low-Mass Structures (DAMAS); University of Lorraine; Metz France
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65
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Patala S. Approximating coincidence – turning a new page for bicrystallography. Acta Crystallogr A Found Adv 2017; 73:85-86. [DOI: 10.1107/s2053273317003321] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 02/28/2017] [Indexed: 11/10/2022] Open
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66
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Morphologies of tungsten nanotendrils grown under helium exposure. Sci Rep 2017; 7:42315. [PMID: 28195125 PMCID: PMC5307965 DOI: 10.1038/srep42315] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 12/30/2016] [Indexed: 11/16/2022] Open
Abstract
Nanotendril “fuzz” will grow under He bombardment under tokamak-relevant conditions on tungsten plasma-facing materials in a magnetic fusion energy device. We have grown tungsten nanotendrils at low (50 eV) and high (12 keV) He bombardment energy, in the range 900–1000 °C, and characterized them using electron microscopy. Low energy tendrils are finer (~22 nm diameter) than high-energy tendrils (~176 nm diameter), and low-energy tendrils have a smoother surface than high-energy tendrils. Cavities were omnipresent and typically ~5–10 nm in size. Oxygen was present at tendril surfaces, but tendrils were all BCC tungsten metal. Electron diffraction measured tendril growth axes and grain boundary angle/axis pairs; no preferential growth axes or angle/axis pairs were observed, and low-energy fuzz grain boundaries tended to be high angle; high energy tendril grain boundaries were not observed. We speculate that the strong tendency to high-angle grain boundaries in the low-energy tendrils implies that as the tendrils twist or bend, strain must accumulate until nucleation of a grain boundary is favorable compared to further lattice rotation. The high-energy tendrils consisted of very large (>100 nm) grains compared to the tendril size, so the nature of the high energy irradiation must enable faster growth with less lattice rotation.
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67
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Rice KP, Chen Y, Keller RR, Stoykovich MP. Beam broadening in transmission and conventional EBSD. Micron 2017; 95:42-50. [PMID: 28192763 DOI: 10.1016/j.micron.2016.12.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 12/28/2016] [Accepted: 12/28/2016] [Indexed: 10/20/2022]
Abstract
Transmission electron backscatter diffraction (t-EBSD) has become a routine technique for crystal orientation mapping when ultrahigh resolution is needed and has demonstrated advantages in the characterization of nanoscale and micron-sized samples (Babinsky et al., 2015). In this work, we use experimental measurements and simulations to compare the resolution of the transmission and conventional reflection EBSD techniques across a range of sample volumes and characterization conditions. Monte Carlo simulations of electron trajectories provide the opportunity to estimate beam size and effective resolution, as well as electron flux, as a function of sample thickness or incident beam energy in t-EBSD. Increasing incident beam energy is shown to negatively impact beam diameter in some cases, and the effect of thinning a sample for conventional EBSD is shown to improve characterization resolution but dramatically decrease the number of high-loss electrons backscattered to the detector. In addition to considering spatial resolution when implementing EBSD techniques, it is found that maintaining a high yield of diffracted electrons to the detector is also of critical importance, which is supported by experimental results. Consequently, this work provides key insights into the nature of electron scattering and probe volume for the practical implementation of both transmission and reflection EBSD techniques.
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Affiliation(s)
- Katherine P Rice
- Cameca Instruments, 5500 Nobel Dr., Madison, WI 53711, United States.
| | - Yimeng Chen
- Cameca Instruments, 5500 Nobel Dr., Madison, WI 53711, United States
| | - Robert R Keller
- Applied Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, CO 80305, United States
| | - Mark P Stoykovich
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, United States.
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68
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Burch MJ, Fancher CM, Patala S, De Graef M, Dickey EC. Mapping 180° polar domains using electron backscatter diffraction and dynamical scattering simulations. Ultramicroscopy 2017; 173:47-51. [DOI: 10.1016/j.ultramic.2016.11.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 11/02/2016] [Accepted: 11/17/2016] [Indexed: 11/29/2022]
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69
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Valery A, Pofelski A, Clément L, Lorut F, Rauch E. TEM illumination settings study for optimum spatial resolution and indexing reliability in crystal orientation mappings. Micron 2017; 92:43-50. [DOI: 10.1016/j.micron.2016.11.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 11/08/2016] [Accepted: 11/08/2016] [Indexed: 10/20/2022]
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70
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Liu S, Ma X, Li L, Zhang L, Trimby PW, Liao X, Li Y, Zhao Y, Zhu Y. Effect of triple junctions on deformation twinning in a nanostructured Cu-Zn alloy: A statistical study using transmission Kikuchi diffraction. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2016; 7:1501-1506. [PMID: 28144500 PMCID: PMC5238639 DOI: 10.3762/bjnano.7.143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 10/04/2016] [Indexed: 06/06/2023]
Abstract
Scanning electron microscopy transmission Kikuchi diffraction is able to identify twins in nanocrystalline material, regardless of their crystallographic orientation. In this study, it was employed to characterize deformation twins in Cu/10 wt % Zn processed by high-pressure torsion. It was found that in 83% of grains containing twins, at least one twin intersects with a triple junction. This suggests that triple junctions could have promoted the nucleation of deformation twins. It should be cautioned that this technique might be unable to detect extremely small nanoscale twins thinner than its step size.
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Affiliation(s)
- Silu Liu
- Nano Structural Materials Center, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Xiaolong Ma
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Lingzhen Li
- Nano Structural Materials Center, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Liwen Zhang
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Patrick W Trimby
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006, Australia
| | - Xiaozhou Liao
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Yusheng Li
- Nano Structural Materials Center, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Yonghao Zhao
- Nano Structural Materials Center, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Yuntian Zhu
- Nano Structural Materials Center, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA
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71
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Li CW, Han LZ, Luo XM, Liu QD, Gu JF. Fine structure characterization of martensite/austenite constituent in low-carbon low-alloy steel by transmission electron forward scatter diffraction. J Microsc 2016; 264:252-258. [PMID: 27571433 DOI: 10.1111/jmi.12465] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 07/02/2016] [Accepted: 08/02/2016] [Indexed: 11/30/2022]
Abstract
Transmission electron forward scatter diffraction and other characterization techniques were used to investigate the fine structure and the variant relationship of the martensite/austenite (M/A) constituent of the granular bainite in low-carbon low-alloy steel. The results demonstrated that the M/A constituents were distributed in clusters throughout the bainitic ferrite. Lath martensite was the main component of the M/A constituent, where the relationship between the martensite variants was consistent with the Nishiyama-Wassermann orientation relationship and only three variants were found in the M/A constituent, suggesting that the variants had formed in the M/A constituent according to a specific mechanism. Furthermore, the Σ3 boundaries in the M/A constituent were much longer than their counterparts in the bainitic ferrite region. The results indicate that transmission electron forward scatter diffraction is an effective method of crystallographic analysis for nanolaths in M/A constituents.
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Affiliation(s)
- C W Li
- Institute of Materials Modification and Modeling, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, P.R. China
| | - L Z Han
- Institute of Materials Modification and Modeling, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, P.R. China
| | - X M Luo
- Institute of Materials Modification and Modeling, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, P.R. China
| | - Q D Liu
- Institute of Materials Modification and Modeling, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, P.R. China
| | - J F Gu
- Institute of Materials Modification and Modeling, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, P.R. China.
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72
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Jacob DE, Piazolo S, Schreiber A, Trimby P. Redox-freezing and nucleation of diamond via magnetite formation in the Earth's mantle. Nat Commun 2016; 7:11891. [PMID: 27327434 PMCID: PMC5411731 DOI: 10.1038/ncomms11891] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 05/10/2016] [Indexed: 11/23/2022] Open
Abstract
Diamonds and their inclusions are unique probes into the deep Earth, tracking the deep carbon cycle to >800 km. Understanding the mechanisms of carbon mobilization and freezing is a prerequisite for quantifying the fluxes of carbon in the deep Earth. Here we show direct evidence for the formation of diamond by redox reactions involving FeNi sulfides. Transmission Kikuchi Diffraction identifies an arrested redox reaction from pyrrhotite to magnetite included in diamond. The magnetite corona shows coherent epitaxy with relict pyrrhotite and diamond, indicating that diamond nucleated on magnetite. Furthermore, structures inherited from h-Fe3O4 define a phase transformation at depths of 320–330 km, the base of the Kaapvaal lithosphere. The oxidation of pyrrhotite to magnetite is an important trigger of diamond precipitation in the upper mantle, explaining the presence of these phases in diamonds. Diamonds provide a window into deep Earth processes and can be used to understand the deep carbon cycle. Here, Jacob et al. show that diamond precipitation can be triggered by the oxidation of pyrrhotite to magnetite at the base of a cratonic lithosphere, providing insight into diamond formation.
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Affiliation(s)
- Dorrit E Jacob
- Australian Research Council Centre of Excellence for Core to Crust Fluid Systems and Department of Earth and Planetary Sciences, Macquarie University, North Ryde, New South Wales 2109, Australia
| | - Sandra Piazolo
- Australian Research Council Centre of Excellence for Core to Crust Fluid Systems and Department of Earth and Planetary Sciences, Macquarie University, North Ryde, New South Wales 2109, Australia
| | - Anja Schreiber
- GeoForschungsZentrum Potsdam, Telegrafenberg C155, Potsdam D-14473, Germany
| | - Patrick Trimby
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, New South Wales 2006, Australia
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73
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Mateo D, Esteve-Adell I, Albero J, Royo JFS, Primo A, Garcia H. 111 oriented gold nanoplatelets on multilayer graphene as visible light photocatalyst for overall water splitting. Nat Commun 2016; 7:11819. [PMID: 27264495 PMCID: PMC4897748 DOI: 10.1038/ncomms11819] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 05/03/2016] [Indexed: 12/15/2022] Open
Abstract
Development of renewable fuels from solar light appears as one of the main current challenges in energy science. A plethora of photocatalysts have been investigated to obtain hydrogen and oxygen from water and solar light in the last decades. However, the photon-to-hydrogen molecule conversion is still far from allowing real implementation of solar fuels. Here we show that 111 facet-oriented gold nanoplatelets on multilayer graphene films deposited on quartz is a highly active photocatalyst for simulated sunlight overall water splitting into hydrogen and oxygen in the absence of sacrificial electron donors, achieving hydrogen production rate of 1.2 molH2 per gcomposite per h. This photocatalytic activity arises from the gold preferential orientation and the strong gold–graphene interaction occurring in the composite system. A plethora of photocatalysts have been investigated in order to obtain solar fuels but the photon-to-hydrogen molecule conversion is generally remains low. Here the authors show that 111 facet oriented gold nanoplatelets on multilayer graphene films is an active photocatalyst for overall water splitting.
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Affiliation(s)
- Diego Mateo
- Instituto de Tecnología Química, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, Avenida de los Naranjos s/n, 46022 Valencia, Spain
| | - Iván Esteve-Adell
- Instituto de Tecnología Química, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, Avenida de los Naranjos s/n, 46022 Valencia, Spain
| | - Josep Albero
- Instituto de Tecnología Química, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, Avenida de los Naranjos s/n, 46022 Valencia, Spain
| | - Juan F Sánchez Royo
- ICMUV, Instituto de Ciencia de Materiales, Universidad de Valencia, PO Box 22085, 46071 Valencia, Spain
| | - Ana Primo
- Instituto de Tecnología Química, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, Avenida de los Naranjos s/n, 46022 Valencia, Spain
| | - Hermenegildo Garcia
- Instituto de Tecnología Química, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, Avenida de los Naranjos s/n, 46022 Valencia, Spain
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74
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WANG Y, KONG M, LIU Z, LIN C, ZENG Y. Effect of microscope parameter and specimen thickness of spatial resolution of transmission electron backscatter diffraction. J Microsc 2016; 264:34-40. [DOI: 10.1111/jmi.12413] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 02/24/2016] [Accepted: 03/25/2016] [Indexed: 11/26/2022]
Affiliation(s)
- Y.Z. WANG
- The State Key Lab of High Performance Ceramics and Superfine Microstructure; Shanghai Institute of Ceramics; Chinese Academy of Sciences; Shanghai China
| | - M.G. KONG
- Key Laboratory of Materials Physics; Institute of Solid State Physics; Chinese Academy of Science; Hefei Anhui China
| | - Z.W. LIU
- The State Key Lab of High Performance Ceramics and Superfine Microstructure; Shanghai Institute of Ceramics; Chinese Academy of Sciences; Shanghai China
| | - C.C. LIN
- The State Key Lab of High Performance Ceramics and Superfine Microstructure; Shanghai Institute of Ceramics; Chinese Academy of Sciences; Shanghai China
| | - Y. ZENG
- The State Key Lab of High Performance Ceramics and Superfine Microstructure; Shanghai Institute of Ceramics; Chinese Academy of Sciences; Shanghai China
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75
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Piazolo S, La Fontaine A, Trimby P, Harley S, Yang L, Armstrong R, Cairney JM. Deformation-induced trace element redistribution in zircon revealed using atom probe tomography. Nat Commun 2016; 7:10490. [PMID: 26868040 PMCID: PMC4754339 DOI: 10.1038/ncomms10490] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 12/18/2015] [Indexed: 11/09/2022] Open
Abstract
Trace elements diffuse negligible distances through the pristine crystal lattice in minerals: this is a fundamental assumption when using them to decipher geological processes. For example, the reliable use of the mineral zircon (ZrSiO4) as a U-Th-Pb geochronometer and trace element monitor requires minimal radiogenic isotope and trace element mobility. Here, using atom probe tomography, we document the effects of crystal-plastic deformation on atomic-scale elemental distributions in zircon revealing sub-micrometre-scale mechanisms of trace element mobility. Dislocations that move through the lattice accumulate U and other trace elements. Pipe diffusion along dislocation arrays connected to a chemical or structural sink results in continuous removal of selected elements (for example, Pb), even after deformation has ceased. However, in disconnected dislocations, trace elements remain locked. Our findings have important implications for the use of zircon as a geochronometer, and highlight the importance of deformation on trace element redistribution in minerals and engineering materials.
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Affiliation(s)
- Sandra Piazolo
- Australian Research Council Centre of Excellence for Core to Crust Fluid Systems/GEMOC, Department of Earth and Planetary Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Alexandre La Fontaine
- Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Patrick Trimby
- Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Simon Harley
- School of Geosciences, Grant Institute, University of Edinburgh, Edinburgh EH9 3JW, UK
| | - Limei Yang
- Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Richard Armstrong
- Research School of Earth Sciences, Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - Julie M Cairney
- Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales 2006, Australia
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76
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Winkelmann A, Nolze G, Vos M, Salvat-Pujol F, Werner WSM. Physics-based simulation models for EBSD: advances and challenges. ACTA ACUST UNITED AC 2016. [DOI: 10.1088/1757-899x/109/1/012018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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77
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Fundenberger J, Bouzy E, Goran D, Guyon J, Yuan H, Morawiec A. Orientation mapping by transmission-SEM with an on-axis detector. Ultramicroscopy 2016; 161:17-22. [DOI: 10.1016/j.ultramic.2015.11.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 10/30/2015] [Accepted: 11/06/2015] [Indexed: 10/22/2022]
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78
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Felfer P, McCarroll I, Macauley C, Cairney JM. A simple approach to atom probe sample preparation by using shadow masks. Ultramicroscopy 2016; 160:163-167. [DOI: 10.1016/j.ultramic.2015.09.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 09/03/2015] [Accepted: 09/11/2015] [Indexed: 10/23/2022]
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79
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Hofer C, Bliznuk V, Verdiere A, Petrov R, Winkelhofer F, Clemens H, Primig S. Correlative microscopy of a carbide-free bainitic steel. Micron 2015; 81:1-7. [PMID: 26642344 DOI: 10.1016/j.micron.2015.10.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Revised: 10/22/2015] [Accepted: 10/27/2015] [Indexed: 10/22/2022]
Abstract
In this work a carbide-free bainitic steel was examined by a novel correlative microscopy approach using transmission Kikuchi diffraction (TKD) and transmission electron microscopy (TEM). The individual microstructural constituents could be identified by TKD based on their different crystal structure for bainitic ferrite and retained austenite and by image quality for the martensite-austenite (M-A) constituent. Subsequently, the same area was investigated in the TEM and a good match of these two techniques regarding the identification of the area position and crystal orientation could be proven. Additionally, the M-A constituent was examined in the TEM for the first time after preceded unambiguous identification using a correlative microscopy approach. The selected area diffraction pattern showed satellites around the main reflexes which might indicate a structural modulation.
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Affiliation(s)
- Christina Hofer
- Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, Franz-Josef-Straße 18, A-8700 Leoben, Austria.
| | - Vitaliy Bliznuk
- Department of Materials Science and Engineering, Ghent University, Technologiepark 903, B-9052 Zwijnaarde, Ghent, Belgium
| | - An Verdiere
- Department of Materials Science and Engineering, Ghent University, Technologiepark 903, B-9052 Zwijnaarde, Ghent, Belgium
| | - Roumen Petrov
- Department of Materials Science and Engineering, Ghent University, Technologiepark 903, B-9052 Zwijnaarde, Ghent, Belgium; Department Materials Science and Engineering, TU Delft, Mekelweg 2, NL-2628CD Delft, The Netherlands
| | - Florian Winkelhofer
- Research and Development - Business Unit Coil, voestalpine Stahl GmbH, voestalpine-Straße 3, A-4020 Linz, Austria
| | - Helmut Clemens
- Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, Franz-Josef-Straße 18, A-8700 Leoben, Austria
| | - Sophie Primig
- Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, Franz-Josef-Straße 18, A-8700 Leoben, Austria
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80
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Grain boundary study of technically pure molybdenum by combining APT and TKD. Ultramicroscopy 2015; 159 Pt 2:445-51. [DOI: 10.1016/j.ultramic.2015.05.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 05/11/2015] [Accepted: 05/14/2015] [Indexed: 11/18/2022]
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81
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de Jeer LTH, Ribas Gomes D, Nijholt JE, van Bremen R, Ocelík V, De Hosson JTM. Formation of Nanoporous Gold Studied by Transmission Electron Backscatter Diffraction. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2015; 21:1387-1397. [PMID: 26514692 DOI: 10.1017/s1431927615015329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Transmission electron backscatter diffraction (t-EBSD) was used to investigate the effect of dealloying on the microstructure of 140-nm thin gold foils. Statistical and local comparisons of the microstructure between the nonetched and nanoporous gold foils were made. Analyses of crystallographic texture, misorientation distribution, and grain structure clearly prove that during the dealloying manufacturing process of nanoporous materials the crystallographic texture is enhanced significantly with a clear decrease of internal strain, whereas maintaining the grain structure.
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Affiliation(s)
- Leo T H de Jeer
- Department of Applied Physics,Zernike Institute for Advanced Materials,University of Groningen,Nijenborgh 4,9747 AG Groningen,The Netherlands
| | - Diego Ribas Gomes
- Department of Applied Physics,Zernike Institute for Advanced Materials,University of Groningen,Nijenborgh 4,9747 AG Groningen,The Netherlands
| | - Jorrit E Nijholt
- Department of Applied Physics,Zernike Institute for Advanced Materials,University of Groningen,Nijenborgh 4,9747 AG Groningen,The Netherlands
| | - Rik van Bremen
- Department of Applied Physics,Zernike Institute for Advanced Materials,University of Groningen,Nijenborgh 4,9747 AG Groningen,The Netherlands
| | - Václav Ocelík
- Department of Applied Physics,Zernike Institute for Advanced Materials,University of Groningen,Nijenborgh 4,9747 AG Groningen,The Netherlands
| | - Jeff Th M De Hosson
- Department of Applied Physics,Zernike Institute for Advanced Materials,University of Groningen,Nijenborgh 4,9747 AG Groningen,The Netherlands
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82
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Height-resolved quantification of microstructure and texture in polycrystalline thin films using TEM orientation mapping. Ultramicroscopy 2015; 159 Pt 1:112-23. [DOI: 10.1016/j.ultramic.2015.08.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 07/30/2015] [Accepted: 08/23/2015] [Indexed: 11/15/2022]
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83
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Primo A, Esteve-Adell I, Coman SN, Candu N, Parvulescu VI, Garcia H. One-Step Pyrolysis Preparation of 1.1.1 Oriented Gold Nanoplatelets Supported on Graphene and Six Orders of Magnitude Enhancement of the Resulting Catalytic Activity. Angew Chem Int Ed Engl 2015; 55:607-12. [DOI: 10.1002/anie.201508908] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 10/26/2015] [Indexed: 11/06/2022]
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84
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Primo A, Esteve-Adell I, Coman SN, Candu N, Parvulescu VI, Garcia H. One-Step Pyrolysis Preparation of 1.1.1 Oriented Gold Nanoplatelets Supported on Graphene and Six Orders of Magnitude Enhancement of the Resulting Catalytic Activity. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201508908] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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85
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Abbasi M, Kim DI, Guim HU, Hosseini M, Danesh-Manesh H, Abbasi M. Application of Transmitted Kikuchi Diffraction in Studying Nano-oxide and Ultrafine Metallic Grains. ACS NANO 2015; 9:10991-11002. [PMID: 26482120 DOI: 10.1021/acsnano.5b04296] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Transmitted Kikuchi diffraction (TKD) is an emerging SEM-based technique that enables investigation of highly refined grain structures. It offers higher spatial resolution by utilizing conventional electron backscattered diffraction equipment on electron-transparent samples. A successful attempt has been made to reveal nano-oxide grain structures as well as ultrafine severely deformed metallic grains. The effect of electron beam current was studied. Higher beam currents enhance pattern contrast and intensity. Lower detector exposure times could be employed to accelerate the acquisition time and minimize drift and carbon contamination. However, higher beam currents increase the electron interaction volume and compromise the spatial resolution. Lastly, TKD results were compared to orientation mapping results in TEM (ASTAR). Results indicate that a combination of TKD and EDS is a capable tool to characterize nano-oxide grains such as Al2O3 and Cr2O3 with similar crystal structures.
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Affiliation(s)
- Majid Abbasi
- High Temperature Energy Materials Research Center, Korea Institute of Science and Technology , Seoul 02792, Republic of Korea
| | - Dong-Ik Kim
- High Temperature Energy Materials Research Center, Korea Institute of Science and Technology , Seoul 02792, Republic of Korea
| | - Hwan-Uk Guim
- Korea Basic Science Institute , Daejeon 34133, Republic of Korea
| | - Morteza Hosseini
- Department of Materials Science and Engineering, Shiraz University , Shiraz, Iran
| | - Habib Danesh-Manesh
- Department of Materials Science and Engineering, Shiraz University , Shiraz, Iran
| | - Mehrdad Abbasi
- Department of Mining and Metallurgy, Amirkabir University of Technology , Tehran, Iran
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86
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van Bremen R, Ribas Gomes D, de Jeer LTH, Ocelík V, De Hosson JTM. On the optimum resolution of transmission-electron backscattered diffraction (t-EBSD). Ultramicroscopy 2015; 160:256-264. [PMID: 26579885 DOI: 10.1016/j.ultramic.2015.10.025] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Revised: 10/22/2015] [Accepted: 10/29/2015] [Indexed: 10/22/2022]
Abstract
The work presented aims at determining the optimum physical resolution of the transmission-electron backscattered diffraction (t-EBSD) technique. The resolution depends critically on intrinsic factors such as the density, atomic number and thickness of the specimen but also on the extrinsic experimental set-up of the electron beam voltage, specimen tilt and detector position. In the present study, the so-called physical resolution of a typical t-EBSD set-up was determined with the use of Monte Carlo simulations and confronted to experimental findings. In the case of a thin Au film of 20 nm, the best resolution obtained was 9 nm whereas for a 100 nm Au film the best resolution was 66 nm. The precise dependence of resolution on thickness was found to vary differently depending on the specific elements involved. This means that the resolution of each specimen should be determined individually. Experimentally the median probe size of the t-EBSD for a 140 nm thick AuAg specimen was measured to be 87 nm. The first and third quartiles of the probe size measurements were found to be 60 nm and 118 nm. Simulation of this specimen resulted in a resolution of 94 nm which fits between these quartiles.
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Affiliation(s)
- R van Bremen
- Department of Applied Physics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - D Ribas Gomes
- Department of Applied Physics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - L T H de Jeer
- Department of Applied Physics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - V Ocelík
- Department of Applied Physics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| | - J Th M De Hosson
- Department of Applied Physics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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87
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Pérez-Arantegui J, Larrea A. Electron backscattering diffraction as a complementary analytical approach to the microstructural characterization of ancient materials by electron microscopy. Trends Analyt Chem 2015. [DOI: 10.1016/j.trac.2015.03.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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88
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Using transmission Kikuchi diffraction to study intergranular stress corrosion cracking in type 316 stainless steels. Micron 2015; 75:1-10. [DOI: 10.1016/j.micron.2015.04.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 04/20/2015] [Accepted: 04/20/2015] [Indexed: 11/22/2022]
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89
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Proust G, Retraint D, Chemkhi M, Roos A, Demangel C. Electron Backscatter Diffraction and Transmission Kikuchi Diffraction Analysis of an Austenitic Stainless Steel Subjected to Surface Mechanical Attrition Treatment and Plasma Nitriding. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2015; 21:919-926. [PMID: 26139391 DOI: 10.1017/s1431927615000793] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Austenitic 316L stainless steel can be used for orthopedic implants due to its biocompatibility and high corrosion resistance. Its range of applications in this field could be broadened by improving its wear and friction properties. Surface properties can be modified through surface hardening treatments. The effects of such treatments on the microstructure of the alloy were investigated here. Surface Mechanical Attrition Treatment (SMAT) is a surface treatment that enhances mechanical properties of the material surface by creating a thin nanocrystalline layer. After SMAT, some specimens underwent a plasma nitriding process to further enhance their surface properties. Using electron backscatter diffraction, transmission Kikuchi diffraction, energy dispersive spectroscopy, and transmission electron microscopy, the microstructural evolution of the stainless steel after these different surface treatments was characterized. Microstructural features investigated include thickness of the nanocrystalline layer, size of the grains within the nanocrystalline layer, and depth of diffusion of nitrogen atoms within the material.
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Affiliation(s)
- Gwénaëlle Proust
- 1School of Civil Engineering,The University of Sydney,NSW 2006,Australia
| | - Delphine Retraint
- 2Charles Delaunay Institute,University of Technology of Troyes (UTT),LASMIS,UMR STMR CNRS 6279,12 rue Marie Curie,CS 42060,10004 Troyes Cedex,France
| | - Mahdi Chemkhi
- 2Charles Delaunay Institute,University of Technology of Troyes (UTT),LASMIS,UMR STMR CNRS 6279,12 rue Marie Curie,CS 42060,10004 Troyes Cedex,France
| | - Arjen Roos
- 2Charles Delaunay Institute,University of Technology of Troyes (UTT),LASMIS,UMR STMR CNRS 6279,12 rue Marie Curie,CS 42060,10004 Troyes Cedex,France
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90
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Herbig M, Choi P, Raabe D. Combining structural and chemical information at the nanometer scale by correlative transmission electron microscopy and atom probe tomography. Ultramicroscopy 2015; 153:32-9. [PMID: 25723104 DOI: 10.1016/j.ultramic.2015.02.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 02/05/2015] [Accepted: 02/12/2015] [Indexed: 11/26/2022]
Abstract
In many cases, the three-dimensional reconstructions from atom probe tomography (APT) are not sufficiently accurate to resolve crystallographic features such as lattice planes, shear bands, stacking faults, dislocations or grain boundaries. Hence, correlative crystallographic characterization is required in addition to APT at the exact same location of the specimen. Also, for the site-specific preparation of APT tips containing regions of interest (e.g. grain boundaries) correlative electron microscopy is often inevitable. Here we present a versatile experimental setup that enables performing correlative focused ion beam milling, transmission electron microscopy (TEM), and APT under optimized characterization conditions. The setup was designed for high throughput, robustness and practicability. We demonstrate that atom probe tips can be characterized by TEM in the same way as a standard TEM sample. In particular, the use of scanning nanobeam diffraction provides valuable complementary crystallographic information when being performed on atom probe tips. This technique enables the measurement of orientation and phase maps as known from electron backscattering diffraction with a spatial resolution down to one nanometer.
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Affiliation(s)
- M Herbig
- Max-Planck-Institut für Eisenforschung, Department of Microstructure Physics and Alloy Design, 40237 Düsseldorf, Germany.
| | - P Choi
- Max-Planck-Institut für Eisenforschung, Department of Microstructure Physics and Alloy Design, 40237 Düsseldorf, Germany
| | - D Raabe
- Max-Planck-Institut für Eisenforschung, Department of Microstructure Physics and Alloy Design, 40237 Düsseldorf, Germany
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91
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Birosca S, Ding R, Ooi S, Buckingham R, Coleman C, Dicks K. Nanostructure characterisation of flow-formed Cr-Mo-V steel using transmission Kikuchi diffraction technique. Ultramicroscopy 2015; 153:1-8. [PMID: 25697460 DOI: 10.1016/j.ultramic.2015.02.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 02/02/2015] [Accepted: 02/07/2015] [Indexed: 10/24/2022]
Abstract
Nowadays flow-forming has become a desired near net shape manufacturing method as it provides excellent mechanical properties with improved surface finish and significant manufacturing cost reduction. However, the material is subjected to excessive plastic deformation during flow-forming process, generating a very fine and complex microstructure. In addition, the intense dislocation density and residual stress that is generated in the component during processing makes the microstructure characterisation using conventional micro-analytical tools challenging. Thus, the microstructure/property relationship study in such a material is rather difficult. In the present study a flow-formed Cr-Mo-V steel nanostructure and crystallographic texture were characterised by means of Transmission Kikuchi Diffraction (TKD). Here, TKD is shown to be a powerful technique in revealing very fine martensite laths within an austenite matrix. Moreover, fine precipitates in the order of 20-70 nm on the martensite lath boundaries were clearly imaged and characterised. This greatly assisted in understanding the preferable site formation of the carbides in such a complex microstructure. The results showed that the actual TKD spatial resolution was in the range of 5-10 nm using 25 kV for flow-formed Cr-Mo-V steel.
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Affiliation(s)
- S Birosca
- Materials Research Centre, College of Engineering, Swansea University, Singleton Park, Swansea SA2 8PP, UK.
| | - R Ding
- School of Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - S Ooi
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, UK
| | - R Buckingham
- Materials Research Centre, College of Engineering, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - C Coleman
- Materials Research Centre, College of Engineering, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - K Dicks
- Oxford Instruments NanoAnalysis, Halifax Road, High Wycombe, Buckinghamshire HP12 3SE, UK
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92
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Estimation of dislocation density from precession electron diffraction data using the Nye tensor. Ultramicroscopy 2015; 153:9-21. [PMID: 25697461 DOI: 10.1016/j.ultramic.2015.02.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 01/26/2015] [Accepted: 02/07/2015] [Indexed: 11/24/2022]
Abstract
The Nye tensor offers a means to estimate the geometrically necessary dislocation density of a crystalline sample based on measurements of the orientation changes within individual crystal grains. In this paper, the Nye tensor theory is applied to precession electron diffraction automated crystallographic orientation mapping (PED-ACOM) data acquired using a transmission electron microscope (TEM). The resulting dislocation density values are mapped in order to visualize the dislocation structures present in a quantitative manner. These density maps are compared with other related methods of approximating local strain dependencies in dislocation-based microstructural transitions from orientation data. The effect of acquisition parameters on density measurements is examined. By decreasing the step size and spot size during data acquisition, an increasing fraction of the dislocation content becomes accessible. Finally, the method described herein is applied to the measurement of dislocation emission during in situ annealing of Cu in TEM in order to demonstrate the utility of the technique for characterizing microstructural dynamics.
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93
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Hu J, Garner A, Ni N, Gholinia A, Nicholls RJ, Lozano-Perez S, Frankel P, Preuss M, Grovenor CR. Identifying suboxide grains at the metal–oxide interface of a corroded Zr–1.0%Nb alloy using (S)TEM, transmission-EBSD and EELS. Micron 2015; 69:35-42. [DOI: 10.1016/j.micron.2014.10.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 10/20/2014] [Accepted: 10/20/2014] [Indexed: 11/26/2022]
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94
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Wright SI, Nowell MM, de Kloe R, Camus P, Rampton T. Electron imaging with an EBSD detector. Ultramicroscopy 2015; 148:132-145. [DOI: 10.1016/j.ultramic.2014.10.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 10/09/2014] [Accepted: 10/13/2014] [Indexed: 10/24/2022]
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95
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Bocker C, Kracker M, Rüssel C. Replica extraction method on nanostructured gold coatings and orientation determination combining SEM and TEM techniques. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2014; 20:1654-1661. [PMID: 25313465 DOI: 10.1017/s1431927614013336] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In the field of electron microscopy the replica technique is known as an indirect method and also as an extraction method that is usually applied on metallurgical samples. This contribution describes a fast and simple transmission electron microscopic (TEM) sample preparation by complete removal of nanoparticles from a substrate surface that allows the study of growth mechanisms of nanostructured coatings. The comparison and combination of advanced diffraction techniques in the TEM and scanning electron microscopy (SEM) provide possibilities for operators with access to both facilities. The analysis of TEM-derived diffraction patterns (convergent beam electron diffraction) in the SEM/electron backscatter diffraction software simplifies the application, especially when the patterns are not aligned along a distinct zone axis. The study of the TEM sample directly by SEM and transmission Kikuchi diffraction allows cross-correlation with the TEM results.
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Affiliation(s)
- Christian Bocker
- Otto-Schott-Institut,University Jena,Fraunhoferstr 6,07743 Jena,Germany
| | - Michael Kracker
- Otto-Schott-Institut,University Jena,Fraunhoferstr 6,07743 Jena,Germany
| | - Christian Rüssel
- Otto-Schott-Institut,University Jena,Fraunhoferstr 6,07743 Jena,Germany
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96
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Brodusch N, Demers H, Trudeau M, Gauvin R. High-resolution imaging and X-ray microanalysis in the FE-SEM. SURF INTERFACE ANAL 2014. [DOI: 10.1002/sia.5584] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | - Hendrix Demers
- McGill University; University St. Montréal H3A 0C5 Canada
| | | | - Raynald Gauvin
- McGill University; University St. Montréal H3A 0C5 Canada
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97
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Bandli BR, Gunter ME. Scanning electron microscopy and transmitted electron backscatter diffraction examination of asbestos standard reference materials, amphibole particles of differing morphology, and particle phase discrimination from talc ores. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2014; 20:1805-1816. [PMID: 25339300 DOI: 10.1017/s1431927614013415] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Since 1972, when the US Occupational Health and Safety Administration established the first limits on occupational exposure to asbestos fibers, numerous analytical methods employing several microscopy techniques have been developed to identify a group of minerals defined by legislation as asbestos. While transmission electron microscopy (TEM) is implemented in standardized analytical methods, these methods specify the use of selected area electron diffraction. Because of this constraint, the diffraction data a TEM can provide are often underutilized due to challenges associated with collecting and interpreting individual diffraction patterns. It has been shown that transmission electron backscatter diffraction (tEBSD) produces diffraction patterns nearly identical to electron backscatter diffraction, but from smaller crystal domains. This paper explores the utility of tEBSD for characterization of asbestiform particles from reference asbestos materials, a suite of amphibole minerals of varying morphologies to determine if there is a correlation between mineral habit (i.e., crystal form), microscopic particle shape preferred orientation, and mineral specimens from an industrial talc deposit to provide a case study of the utility and limitations of the technique.
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Affiliation(s)
- Bryan R Bandli
- 1Department of Geological Sciences,University of Minnesota,Duluth,1114 Kirby Dr.,229 Heller Hall,Duluth,MN 55812,USA
| | - Mickey E Gunter
- 2Department of Geological Sciences,University of Idaho,875 Perimeter Drive,MS 3022,Moscow,ID 83844,USA
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98
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Yeoh WK, Cui XY, Gault B, De Silva KSB, Xu X, Liu HW, Yen HW, Wong D, Bao P, Larson DJ, Martin I, Li WX, Zheng RK, Wang XL, Dou SX, Ringer SP. On the roles of graphene oxide doping for enhanced supercurrent in MgB2 based superconductors. NANOSCALE 2014; 6:6166-6172. [PMID: 24793305 DOI: 10.1039/c4nr00415a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Due to their graphene-like properties after oxygen reduction, incorporation of graphene oxide (GO) sheets into correlated-electron materials offers a new pathway for tailoring their properties. Fabricating GO nanocomposites with polycrystalline MgB2 superconductors leads to an order of magnitude enhancement of the supercurrent at 5 K/8 T and 20 K/4 T. Herein, we introduce a novel experimental approach to overcome the formidable challenge of performing quantitative microscopy and microanalysis of such composites, so as to unveil how GO doping influences the structure and hence the material properties. Atom probe microscopy and electron microscopy were used to directly image the GO within the MgB2, and we combined these data with computational simulations to derive the property-enhancing mechanisms. Our results reveal synergetic effects of GO, namely, via localized atomic (carbon and oxygen) doping as well as texturing of the crystals, which provide both inter- and intra-granular flux pinning. This study opens up new insights into how low-dimensional nanostructures can be integrated into composites to modify the overall properties, using a methodology amenable to a wide range of applications.
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Affiliation(s)
- W K Yeoh
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, New South Wales 2006, Australia.
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99
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Wright SI, Nowell MM, de Kloe R, Chan L. Orientation precision of electron backscatter diffraction measurements near grain boundaries. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2014; 20:852-863. [PMID: 24576405 DOI: 10.1017/s143192761400035x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Electron backscatter diffraction (EBSD) has become a common technique for measuring crystallographic orientations at spatial resolutions on the order of tens of nanometers and at angular resolutions <0.1°. In a recent search of EBSD papers using Google Scholar™, 60% were found to address some aspect of deformation. Generally, deformation manifests itself in EBSD measurements by small local misorientations. An increase in the local misorientation is often observed near grain boundaries in deformed microstructures. This may be indicative of dislocation pile-up at the boundaries but could also be due to a loss of orientation precision in the EBSD measurements. When the electron beam is positioned at or near a grain boundary, the diffraction volume contains the crystal lattices from the two grains separated by the boundary. Thus, the resulting pattern will contain contributions from both lattices. Such mixed patterns can pose some challenge to the EBSD pattern band detection and indexing algorithms. Through analysis of experimental local misorientation data and simulated pattern mixing, this work shows that some of the rise in local misorientation is an artifact due to the mixed patterns at the boundary but that the rise due to physical phenomena is also observed.
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Affiliation(s)
| | | | - René de Kloe
- 2EDAX BV,Ringbaan Noord 103,5046 AA Tilburg,The Netherlands
| | - Lisa Chan
- 3TESCAN USA,508 Thomson Park Drive,Cranberry TWP,PA 16066,USA
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100
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A novel approach for site-specific atom probe specimen preparation by focused ion beam and transmission electron backscatter diffraction. Ultramicroscopy 2014; 144:9-18. [PMID: 24815026 DOI: 10.1016/j.ultramic.2014.04.003] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 04/04/2014] [Accepted: 04/11/2014] [Indexed: 11/24/2022]
Abstract
Atom probe tomography (APT) is a suitable technique for chemical analyses with almost atomic resolution. However, the time-consuming site-specific specimen preparation can be improved. Recently, transmission electron backscatter diffraction (t-EBSD) has been established for high resolution crystallographic analyses of thin foils. In this paper we present the first successful application of a combined focused ion beam (FIB)/t-EBSD preparation of site-specific APT specimens using the example of grain boundary segregation in technically pure molybdenum. It will be shown that the preparation of a grain boundary can be substantially accelerated by t-EBSD analyses in-between the annular milling FIB procedure in the same microscope. With this combined method, a grain boundary can easily be recognized and positioned in the first 220nm of an APT sample much faster than e.g. with complementary investigations in a transmission electron microscope. Even more, the high resolution technique of t-EBSD gives the opportunity to get crystallographic information of the mapped area and, therefore, an analysis of the grain boundary character to support the interpretation of the APT data files. To optimize this newly developed technique for the application on needle-shaped APT specimens, a parameter study on enhanced background correction, acceleration voltage, and tilt angle was carried out. An acceleration voltage of 30kV at specimen surface tilt angles between -45° and -35° from horizontal plane leads to the best results. Even for molybdenum the observation of crystal orientation data up to about 200nm specimen thickness is possible.
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