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Zhang T, Britton TB. Multi-exposure diffraction pattern fusion applied to enable wider-angle transmission Kikuchi diffraction with direct electron detectors. Ultramicroscopy 2024; 257:113902. [PMID: 38086289 DOI: 10.1016/j.ultramic.2023.113902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 10/27/2023] [Accepted: 12/04/2023] [Indexed: 01/05/2024]
Abstract
Diffraction pattern analysis can be used to reveal the crystalline structure of materials, and this information is used to nano- and micro-structure of advanced engineering materials that enable modern life. For nano-structured materials typically diffraction pattern analysis is performed in the transmission electron microscope (TEM) and TEM diffraction patterns typically have a limited angular range (less than a few degrees) due to the long camera length, and this requires analysis of multiple patterns to probe a unit cell. As a different approach, wide angle Kikuchi patterns can be captured using an on-axis detector in the scanning electron microscope (SEM) with a shorter camera length. These 'transmission Kikuchi diffraction' (TKD) patterns present a direct projection of the unit cell and can be routinely analysed using EBSD-based methods and dynamical diffraction theory. In the present work, we enhance this analysis significantly and present a multi-exposure diffraction pattern fusion method that increases the dynamic range of the detected patterns captured with a Timepix3-based direct electron detector (DED). This method uses an easy-to-apply exposure fusion routine to collect data and extend the dynamic range, as well as normalise the intensity distribution within these very wide (>95°) angle patterns. The potential of this method is demonstrated with full diffraction sphere reprojection and highlight potential of the approach to rapidly probe the structure of nano-structured materials in the scanning electron microscope.
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Affiliation(s)
- Tianbi Zhang
- Department of Materials Engineering, The University of British Columbia, 309-6350 Stores Road, Vancouver, BC V6T 1Z4 Canada
| | - T Ben Britton
- Department of Materials Engineering, The University of British Columbia, 309-6350 Stores Road, Vancouver, BC V6T 1Z4 Canada.
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2
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Zhang T, Britton TB. A simple, static and stage mounted direct electron detector based electron backscatter diffraction system. Micron 2024; 178:103582. [PMID: 38181589 DOI: 10.1016/j.micron.2023.103582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 01/07/2024]
Abstract
To engineer the next generation of advanced materials we must understand their microstructure, and this requires microstructural characterization. This can be achieved through the collection of high contrast, data rich, and insightful microstructural maps. Electron backscatter diffraction (EBSD) has emerged as a popular tool available within the scanning electron microscope (SEM), where maps are realized through the repeat capture and analysis of Kikuchi diffraction patterns. Typical commercial EBSD systems require large and sophisticated detectors that are mounted on the side of the SEM vacuum chamber which can be limiting in terms of widespread access to the technique. In this work, we present an alternative open-hardware solution based upon a compact EBSD system with a simple, static geometry that uses an off-the-shelf direct electron detector co-mounted with a sample. This simple stage is easy to manufacture and improves our knowledge of the diffraction geometry significantly. Microscope and detector control is achieved through software application programming interface (API) integration. After pattern capture, analysis of the diffraction patterns is performed using open-source analysis within AstroEBSD. To demonstrate the potential of this set up, we present two simple EBSD experiments using a line scan and area mapping. We hope that the present system can inspire simpler EBSD system design for widespread access to the EBSD technique and promote the use of open-source software and hardware in the workflow of EBSD experiments.
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Affiliation(s)
- Tianbi Zhang
- Department of Materials Engineering, The University of British Columbia, 309-6350 Stores Road, Vancouver, BC V6T 1Z4, Canada
| | - T Ben Britton
- Department of Materials Engineering, The University of British Columbia, 309-6350 Stores Road, Vancouver, BC V6T 1Z4, Canada.
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3
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DeRonja J, Nowell M, Wright S, Kacher J. Generational assessment of EBSD detectors for cross-correlation-based analysis: From scintillators to direct detection. Ultramicroscopy 2024; 257:113913. [PMID: 38141535 DOI: 10.1016/j.ultramic.2023.113913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 11/17/2023] [Accepted: 12/19/2023] [Indexed: 12/25/2023]
Abstract
Introduced over ten years ago, cross-correlation-based electron backscatter diffraction has enabled high precision measurements of crystallographic rotations and elastic strain gradients at high spatial resolution. Since that time, there have been remarkable improvements in electron detector technology, including the advent of ultra-high speed detectors and the commercialization of direct detectors. In this study, we assess the efficacy of multiple generations of electron detectors for cross-correlation-based analysis using a single crystal Si sample as a reference. We show that, while improvements in precision are modest, there have been significant gains in the rate at which high-quality diffraction patterns can be collected. This has important implications in the size of datasets that can be collected and reduces the impact of drift and sample contamination.
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Affiliation(s)
| | | | | | - Josh Kacher
- Georgia Institute of Technology, Atlanta, GA 30332, United States.
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4
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Zhang T, Paton KA, Britton TB. Characterization of the Performance of a Thin Si-based Timepix3 Detector at 10-30 keV Electron Energies. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:484. [PMID: 37613025 DOI: 10.1093/micmic/ozad067.229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Tianbi Zhang
- Department of Materials Engineering, University of British Columbia, Vancouver, BCCanada
| | - Kirsty A Paton
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of Glasgow, UK; now with PSD Detector Group, Paul Scherrer Institut, Villigen PSI, Switzerland
| | - T Ben Britton
- Department of Materials Engineering, University of British Columbia, Vancouver, BCCanada
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5
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Basha A, Levi G, Houben L, Amrani T, Goldfarb I, Kohn A. Evaluating direct detection detectors for short-range order characterization of amorphous materials by electron scattering. Ultramicroscopy 2023; 249:113737. [PMID: 37037087 DOI: 10.1016/j.ultramic.2023.113737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 03/29/2023] [Accepted: 04/03/2023] [Indexed: 04/12/2023]
Abstract
The introduction of direct electron detectors (DEDs) to transmission electron microscopy has set off the 'resolution revolution', especially for cryoTEM low-dose imaging of soft matter. In comparison to traditional indirect electron detectors such as Charged-Coupled Devices (CCD), DEDs show an improved modulation transfer function (MTF) and detective quantum efficiency (DQE) across all spatial frequencies, as well as faster frame rates which enable single electron counting. The benefits of such characteristics for imaging, spectroscopy and electron holography have been demonstrated previously. However, studies are lacking on the application of DEDs for localized characterization of short- to medium- range-order (SRO, MRO) in amorphous materials using electron scattering. Therefore, we evaluate the performance of a Monolithic Active Pixel Sensor DED for the characterization of SRO and MRO in nanoscale volumes of amorphous materials, using SiO2 and Ta2O5 thin films as test cases. The performance of the detector is compared systematically to electron scattering measurements recorded on an indirect detector (CCD) using 200 keV electrons and electron doses starting at approximately 500e-Å2 . In addition, the effects of sample cooling and energy-filtering on the measured SRO of the oxides were investigated. We demonstrate that the performance of the DED resulted in improved SRO characterization in comparison to that obtained from the CCD measurements. The DED enabled to achieve a larger measured maximal scattering vector, ∼16.51Å compared to ∼151Å, for the CCD. Furthermore, an improved signal-to-noise ratio of approximately two-fold was observed across all spatial frequencies for both 200 keV and 80 keV electrons. These improvements are shown to result from the superior DQE of the DED. Consequently, the DED measurements enabled to determine the coordination numbers of atomic bonds more accurately. We expect that further benefits of the DED for S/MRO characterization will be highlighted for ultra- sensitive materials that cannot withstand electron doses above several e-Å2 .
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Affiliation(s)
- Adham Basha
- Department of Materials Science and Engineering, The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Ramat Aviv, Tel Aviv 6997801, Israel
| | - George Levi
- Department of Materials Science and Engineering, The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Ramat Aviv, Tel Aviv 6997801, Israel
| | - Lothar Houben
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Tamir Amrani
- Department of Materials Science and Engineering, The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Ramat Aviv, Tel Aviv 6997801, Israel
| | - Ilan Goldfarb
- Department of Materials Science and Engineering, The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Ramat Aviv, Tel Aviv 6997801, Israel
| | - Amit Kohn
- Department of Materials Science and Engineering, The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Ramat Aviv, Tel Aviv 6997801, Israel.
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6
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Brodusch N, Brahimi SV, Barbosa De Melo E, Song J, Yue S, Piché N, Gauvin R. Scanning Electron Microscopy versus Transmission Electron Microscopy for Material Characterization: A Comparative Study on High-Strength Steels. SCANNING 2021; 2021:5511618. [PMID: 34025898 PMCID: PMC8112914 DOI: 10.1155/2021/5511618] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/30/2021] [Accepted: 04/22/2021] [Indexed: 05/27/2023]
Abstract
The microstructures of quenched and tempered steels have been traditionally explored by transmission electron microscopy (TEM) rather than scanning electron microscopy (SEM) since TEM offers the high resolution necessary to image the structural details that control the mechanical properties. However, scanning electron microscopes, apart from providing larger area coverage, are commonly available and cheaper to purchase and operate compared to TEM and have evolved considerably in terms of resolution. This work presents detailed comparison of the microstructure characterization of quenched and tempered high-strength steels with TEM and SEM electron channeling contrast techniques. For both techniques, similar conclusions were made in terms of large-scale distribution of martensite lath and plates and nanoscale observation of nanotwins and dislocation structures. These observations were completed with electron backscatter diffraction to assess the martensite size distribution and the retained austenite area fraction. Precipitation was characterized using secondary imaging in the SEM, and a deep learning method was used for image segmentation. In this way, carbide size, shape, and distribution were quantitatively measured down to a few nanometers and compared well with the TEM-based measurements. These encouraging results are intended to help the material science community develop characterization techniques at lower cost and higher statistical significance.
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Affiliation(s)
- Nicolas Brodusch
- McGill Electron Microscopy Research Group, Department of Mining and Materials Engineering, McGill University, Montréal, Québec, Canada H3A 0C5
| | - Salim V. Brahimi
- McGill Hydrogen Embrittlement Facility, Department of Mining and Materials Engineering, McGill University, Montréal, Québec, Canada H3A 0C5
| | - Evelin Barbosa De Melo
- McGill Hydrogen Embrittlement Facility, Department of Mining and Materials Engineering, McGill University, Montréal, Québec, Canada H3A 0C5
| | - Jun Song
- McGill Hydrogen Embrittlement Facility, Department of Mining and Materials Engineering, McGill University, Montréal, Québec, Canada H3A 0C5
| | - Stephen Yue
- McGill Hydrogen Embrittlement Facility, Department of Mining and Materials Engineering, McGill University, Montréal, Québec, Canada H3A 0C5
| | - Nicolas Piché
- Object Research Systems, 760 St-Paul West, Suite 101, Montreal, Quebec, Canada H3C 1M4
| | - Raynald Gauvin
- McGill Electron Microscopy Research Group, Department of Mining and Materials Engineering, McGill University, Montréal, Québec, Canada H3A 0C5
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7
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Caplins BW, Holm JD, White RM, Keller RR. Orientation mapping of graphene using 4D STEM-in-SEM. Ultramicroscopy 2020; 219:113137. [PMID: 33096294 PMCID: PMC8022335 DOI: 10.1016/j.ultramic.2020.113137] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 10/08/2020] [Accepted: 10/11/2020] [Indexed: 11/20/2022]
Abstract
A scanning diffraction technique is implemented in the scanning electron microscope. The technique, referred to as 4D STEM-in-SEM (four-dimensional scanning transmission electron microscopy in the scanning electron microscope), collects a diffraction pattern from each point on a sample which is saved to disk for further analysis. The diffraction patterns are collected using an on-axis lens-coupled phosphor/CCD arrangement. Synchronization between the electron beam and the camera exposure is accomplished with off-the-shelf data acquisition hardware. Graphene is used as a model system to test the sensitivity of the instrumentation and develop some basic analysis techniques. The data show interpretable diffraction patterns from monolayer graphene with integration times as short as 0.5 ms with a beam current of 245 pA (7.65×105 incident electrons per pixel). Diffraction patterns are collected at a rate of ca. 100/s from the mm to nm length scales. Using a grain boundary as a 'knife-edge', the spatial resolution of the technique is demonstrated to be ≤5.6nm (edge-width 25 % to 75 %). Analysis of the orientation of the diffraction patterns yields an angular (orientation) precision of ≤0.19∘ (full width at half maximum) for unsupported monolayer graphene. In addition, it is demonstrated that the 4D datasets have the information content necessary to analyze complex and heterogeneous multilayer graphene films.
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Affiliation(s)
- Benjamin W Caplins
- National Institute of Standards and Technology, Applied Chemicals and Materials Division, Boulder, CO, 80305, United States.
| | - Jason D Holm
- National Institute of Standards and Technology, Applied Chemicals and Materials Division, Boulder, CO, 80305, United States
| | - Ryan M White
- National Institute of Standards and Technology, Applied Chemicals and Materials Division, Boulder, CO, 80305, United States
| | - Robert R Keller
- National Institute of Standards and Technology, Applied Chemicals and Materials Division, Boulder, CO, 80305, United States
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8
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Wang F, Echlin MP, Taylor AA, Shin J, Bammes B, Levin BDA, De Graef M, Pollock TM, Gianola DS. Electron backscattered diffraction using a new monolithic direct detector: High resolution and fast acquisition. Ultramicroscopy 2020; 220:113160. [PMID: 33197699 DOI: 10.1016/j.ultramic.2020.113160] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 10/19/2020] [Accepted: 11/01/2020] [Indexed: 11/19/2022]
Abstract
A monolithic active pixel sensor based direct detector that is optimized for the primary beam energies in scanning electron microscopes is implemented for electron back-scattered diffraction (EBSD) applications. The high detection efficiency of the detector and its large array of pixels allow sensitive and accurate detection of Kikuchi bands arising from primary electron beam excitation energies of 4 keV to 28 keV, with the optimal contrast occurring in the range of 8-16 keV. The diffraction pattern acquisition speed is substantially improved via a sparse sampling mode, resulting from the acquisition of a reduced number of pixels on the detector. Standard inpainting algorithms are implemented to effectively estimate the information in the skipped regions in the acquired diffraction pattern. For EBSD mapping, an acquisition speed as high as 5988 scan points per second is demonstrated, with a tolerable fraction of indexed points and accuracy. The collective capabilities spanning from high angular resolution EBSD patterns to high speed pattern acquisition are achieved on the same detector, facilitating simultaneous detection modalities that enable a multitude of advanced EBSD applications, including lattice strain mapping, structural refinement, low-dose characterization, 3D-EBSD and dynamic in situ EBSD.
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Affiliation(s)
- Fulin Wang
- Materials Department, University of California Santa Barbara, Santa Barbara, CA 93117, USA
| | - McLean P Echlin
- Materials Department, University of California Santa Barbara, Santa Barbara, CA 93117, USA
| | - Aidan A Taylor
- Materials Department, University of California Santa Barbara, Santa Barbara, CA 93117, USA
| | - Jungho Shin
- Materials Department, University of California Santa Barbara, Santa Barbara, CA 93117, USA
| | | | | | - Marc De Graef
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Tresa M Pollock
- Materials Department, University of California Santa Barbara, Santa Barbara, CA 93117, USA
| | - Daniel S Gianola
- Materials Department, University of California Santa Barbara, Santa Barbara, CA 93117, USA.
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9
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EBSD pattern simulations for an interaction volume containing lattice defects. Ultramicroscopy 2020; 218:113088. [DOI: 10.1016/j.ultramic.2020.113088] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 07/26/2020] [Accepted: 08/02/2020] [Indexed: 11/19/2022]
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10
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Ruggles TJ, Yoo YSJ, Dunlap BE, Crimp MA, Kacher J. Correlating results from high resolution EBSD with TEM- and ECCI-based dislocation microscopy: Approaching single dislocation sensitivity via noise reduction. Ultramicroscopy 2019; 210:112927. [PMID: 31923781 DOI: 10.1016/j.ultramic.2019.112927] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 12/20/2019] [Accepted: 12/28/2019] [Indexed: 10/25/2022]
Abstract
High resolution electron backscatter diffraction (HREBSD), an SEM-based diffraction technique, may be used to measure the lattice distortion of a crystalline material and to infer the geometrically necessary dislocation content. Uncertainty in the image correlation process used to compare diffraction patterns leads to an uneven distribution of measurement noise in terms of the lattice distortion, which results in erroneous identification of dislocation type and density. This work presents a method of reducing noise in HREBSD dislocation measurements by removing the effect of the most problematic components of the measured distortion. The method is then validated by comparing with TEM analysis of dislocation pile-ups near a twin boundary in austenitic stainless steel and with ECCI analysis near a nano-indentation on a tantalum oligocrystal. The HREBSD dislocation microscopy technique is able to resolve individual dislocations visible in TEM and ECCI and correctly identify their Burgers vectors.
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Affiliation(s)
- T J Ruggles
- National Institute of Aerospace, Hampton, VA, USA; Sandia National Laboratories, Albuquerque, NM, USA.
| | - Y S J Yoo
- Georgia Institute of Technology, Atlanta, GA, USA
| | - B E Dunlap
- Michigan State University, East Lansing, MI, USA
| | - M A Crimp
- Michigan State University, East Lansing, MI, USA
| | - J Kacher
- Georgia Institute of Technology, Atlanta, GA, USA
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11
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Zhu C, Kaufmann K, Vecchio K. Automated Reconstruction of Spherical Kikuchi Maps. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2019; 25:912-923. [PMID: 31148535 DOI: 10.1017/s1431927619000710] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
An automated approach to fully reconstruct spherical Kikuchi maps from experimentally collected electron backscatter diffraction patterns and overlay each pattern onto its corresponding position on a simulated Kikuchi sphere is presented in this study. This work demonstrates the feasibility of warping any Kikuchi pattern onto its corresponding location of a simulated Kikuchi sphere and reconstructing a spherical Kikuchi map of a known phase based on any set of experimental patterns. This method consists of the following steps after pattern collection: (1) pattern selection based on multiple threshold values; (2) extraction of multiple scan parameters and phase information; (3) generation of a kinematically simulated Kikuchi sphere as the "skeleton" of the spherical Kikuchi map; and (4) overlaying the inverse gnomonic projection of multiple selected patterns after appropriate pattern center calibration and refinement. The proposed method is the first automated approach to reconstructing spherical Kikuchi maps from experimental Kikuchi patterns. It potentially enables more accurate orientation calculation, new pattern center refinement methods, improved dictionary-based pattern matching, and phase identification in the future.
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Affiliation(s)
- Chaoyi Zhu
- Materials Science and Engineering Program, University of CA San Diego,La Jolla, CA 92093,USA
| | - Kevin Kaufmann
- Department of NanoEngineering,University of California San Diego,La Jolla, CA 92093,USA
| | - Kenneth Vecchio
- Materials Science and Engineering Program, University of CA San Diego,La Jolla, CA 92093,USA
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12
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Pattern matching analysis of electron backscatter diffraction patterns for pattern centre, crystal orientation and absolute elastic strain determination – accuracy and precision assessment. Ultramicroscopy 2019; 202:87-99. [DOI: 10.1016/j.ultramic.2019.04.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 03/31/2019] [Accepted: 04/10/2019] [Indexed: 11/18/2022]
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13
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Langlois C, Douillard T, Dubail S, Lafond C, Cazottes S, Silvent J, Delobbe A, Steyer P. Angular resolution expected from iCHORD orientation maps through a revisited ion channeling model. Ultramicroscopy 2019; 202:68-75. [PMID: 30991264 DOI: 10.1016/j.ultramic.2019.03.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 03/01/2019] [Accepted: 03/18/2019] [Indexed: 10/27/2022]
Abstract
Crystalline orientation maps are obtained in a Focused Ion Beam (FIB) microscope using the ion CHanneling ORientation Determination (iCHORD) method, which relies on the channeling phenomenon observed in ion-induced secondary electron images. The current paper focuses on the angular resolution that can be expected from such orientation maps, obtained using a revisited ion channeling model. A specific procedure was developed to evaluate the angular resolution, based on the distribution of orientation errors when evaluating controlled sample disorientation. The main advantage is that no external reference is required. An angular resolution of 1° is obtained on a nickel based sample using standard acquisition conditions. This value fulfills most of the needs in terms of microstructural characterization usually carried out by Electron Back Scattered Diffraction.
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Affiliation(s)
- C Langlois
- Université de Lyon, INSA-Lyon, MATEIS CNRS UMR5510, 7 avenue Jean Capelle, 69621 Villeurbanne, France.
| | - T Douillard
- Université de Lyon, INSA-Lyon, MATEIS CNRS UMR5510, 7 avenue Jean Capelle, 69621 Villeurbanne, France
| | - S Dubail
- Axon Square SAS, 4 la Tuilière, 74140 Sciez, France
| | - C Lafond
- Université de Lyon, INSA-Lyon, MATEIS CNRS UMR5510, 7 avenue Jean Capelle, 69621 Villeurbanne, France
| | - S Cazottes
- Université de Lyon, INSA-Lyon, MATEIS CNRS UMR5510, 7 avenue Jean Capelle, 69621 Villeurbanne, France
| | - J Silvent
- Orsay Physics, 95 Avenue des Monts Auréliens, 13710 Fuveau, France
| | - A Delobbe
- Orsay Physics, 95 Avenue des Monts Auréliens, 13710 Fuveau, France
| | - P Steyer
- Université de Lyon, INSA-Lyon, MATEIS CNRS UMR5510, 7 avenue Jean Capelle, 69621 Villeurbanne, France
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14
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Brodu E, Bouzy E. A New and Unexpected Spatial Relationship Between Interaction Volume and Diffraction Pattern in Electron Microscopy in Transmission. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2018; 24:634-646. [PMID: 30516124 DOI: 10.1017/s1431927618015441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The finding of this study is that the interaction volume in electron microscopy in transmission is well ordered laterally, with a remarkable and unexpected consequence being that lateral subsections of the interaction volume produce subsections of the Kikuchi diffraction pattern. It makes the microstructure of samples directly visible in Kikuchi patterns. This is first illustrated with polycrystalline Ti-10Al-25Nb with an on-axis transmission Kikuchi diffraction set-up in a scanning electron microscope. It is then shown via a Monte Carlo simulation and a large-angle convergent-beam electron diffraction experiment that this phenomenon finds its origin in the nature of the differential elastic and quasi-elastic cross sections. This phenomenon is then quantified by a careful image analysis of Kikuchi patterns recorded across a vertical interface in a silicon sample specifically designed and fabricated. A Monte Carlo simulation reproducing all the geometric parameters is conducted. Experiments and simulations match very well qualitatively, but with a slight quantitativity gap. The specificity of the thermal diffuse scattering cross-section, not available in the simulation, is thought to be responsible for this gap. Beside Kikuchi diffraction, the case of diffraction spots and diffuse background present in the pattern is also discussed.
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Affiliation(s)
- Etienne Brodu
- 1Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3),Université de Lorraine,UMR CNRS 7239,57045 Metz,France
| | - Emmanuel Bouzy
- 1Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3),Université de Lorraine,UMR CNRS 7239,57045 Metz,France
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15
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Imaging with a Commercial Electron Backscatter Diffraction (EBSD) Camera in a Scanning Electron Microscope: A Review. J Imaging 2018. [DOI: 10.3390/jimaging4070088] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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16
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Mingard K, Stewart M, Gee M, Vespucci S, Trager-Cowan C. Practical application of direct electron detectors to EBSD mapping in 2D and 3D. Ultramicroscopy 2018; 184:242-251. [DOI: 10.1016/j.ultramic.2017.09.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 09/11/2017] [Accepted: 09/26/2017] [Indexed: 11/25/2022]
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17
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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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Clough R, Kirkland A. Direct Digital Electron Detectors. ADVANCES IN IMAGING AND ELECTRON PHYSICS 2016. [DOI: 10.1016/bs.aiep.2016.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Zhang L, Li X, Shao Y, Yu J, Wu Y, Hao X, Yin Z, Dai Y, Tian Y, Huo Q, Shen Y, Hua Z, Zhang B. Improving the quality of GaN crystals by using graphene or hexagonal boron nitride nanosheets substrate. ACS APPLIED MATERIALS & INTERFACES 2015; 7:4504-4510. [PMID: 25665033 DOI: 10.1021/am5087775] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The progress in nitrides technology is widely believed to be limited and hampered by the lack of high-quality gallium nitride wafers. Though various epitaxial techniques like epitaxial lateral overgrowth and its derivatives have been used to reduce defect density, there is still plenty of room for the improvement of gallium nitride crystal. Here, we report graphene or hexagonal boron nitride nanosheets can be used to improve the quality of GaN crystal using hydride vapor phase epitaxy methods. These nanosheets were directly deposited on the substrate that is used for the epitaxial growth of GaN crystal. Systematic characterizations of the as-obtained crystal show that quality of GaN crystal is greatly improved. The fabricated light-emitting diodes using the as-obtained GaN crystals emit strong electroluminescence under room illumination. This simple yet effective technique is believed to be applicable in metal-organic chemical vapor deposition systems and will find wide applications on other crystal growth.
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Affiliation(s)
- Lei Zhang
- State Key Lab of Crystal Materials, Shandong University , Jinan 250100, P. R. China
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Chirality determination of quartz crystals using Electron Backscatter Diffraction. Ultramicroscopy 2015; 149:58-63. [DOI: 10.1016/j.ultramic.2014.11.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 11/03/2014] [Accepted: 11/10/2014] [Indexed: 11/30/2022]
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Brodusch N, Demers H, Gauvin R. Dark-field imaging based on post-processed electron backscatter diffraction patterns of bulk crystalline materials in a scanning electron microscope. Ultramicroscopy 2014; 148:123-131. [PMID: 25461589 DOI: 10.1016/j.ultramic.2014.09.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 09/08/2014] [Accepted: 09/21/2014] [Indexed: 11/18/2022]
Abstract
Dark-field (DF) images were acquired in the scanning electron microscope with an offline procedure based on electron backscatter diffraction (EBSD) patterns (EBSPs). These EBSD-DF images were generated by selecting a particular reflection on the electron backscatter diffraction pattern and by reporting the intensity of one or several pixels around this point at each pixel of the EBSD-DF image. Unlike previous studies, the diffraction information of the sample is the basis of the final image contrast with a pixel scale resolution at the EBSP providing DF imaging in the scanning electron microscope. The offline facility of this technique permits the selection of any diffraction condition available in the diffraction pattern and displaying the corresponding image. The high number of diffraction-based images available allows a better monitoring of deformation structures compared to electron channeling contrast imaging (ECCI) which is generally limited to a few images of the same area. This technique was applied to steel and iron specimens and showed its high capability in describing more rigorously the deformation structures around micro-hardness indents. Due to the offline relation between the reference EBSP and the EBSD-DF images, this new technique will undoubtedly greatly improve our knowledge of deformation mechanism and help to improve our understanding of the ECCI contrast mechanisms.
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Affiliation(s)
- Nicolas Brodusch
- McGill University, Mining and Materials Engineering Department, Montréal, Québec, Canada H3A 0C5.
| | - Hendrix Demers
- McGill University, Mining and Materials Engineering Department, Montréal, Québec, Canada H3A 0C5
| | - Raynald Gauvin
- McGill University, Mining and Materials Engineering Department, Montréal, Québec, Canada H3A 0C5
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Britton T, Jiang J, Clough R, Tarleton E, Kirkland A, Wilkinson A. Assessing the precision of strain measurements using electron backscatter diffraction – part 1: Detector assessment. Ultramicroscopy 2013; 135:126-35. [DOI: 10.1016/j.ultramic.2013.08.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 08/08/2013] [Accepted: 08/08/2013] [Indexed: 10/26/2022]
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