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Ge M, Pan Y, Liu X, Zhao Z, Su D. Automatic center identification of electron diffraction with multi-scale transformer networks. Ultramicroscopy 2024; 259:113926. [PMID: 38310650 DOI: 10.1016/j.ultramic.2024.113926] [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: 07/03/2023] [Revised: 12/08/2023] [Accepted: 01/21/2024] [Indexed: 02/06/2024]
Abstract
Selected area electron diffraction (SAED) is a widely used technique for characterizing the structure and measuring lattice parameters of materials. An autonomous analytic method has become an urgent demand for the large-scale SAED data produced from in-situ experiments. In this work, we realize the automatic processing for center identification with a proposed deep segmentation model named the multi-scale Transformer (MS-Trans) network. This algorithm enables robust segmentation of the central spots by combining a novel gated axial-attention module and multi-scale feature fusion. The proposed MS-Trans model shows high precision and robustness, enabling autonomous processing of SAED patterns without any prior knowledge. The application on in-situ SAED data of the oxidation process of FeNi alloy demonstrates its capability of implementing autonomous quantitative processing. © 2017 Elsevier Inc. All rights reserved.
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Affiliation(s)
- Mengshu Ge
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yue Pan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Xiaozhi Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Zhicheng Zhao
- School of Artificial Intelligence, Beijing University of Posts and Telecommunications, Beijing, 100876, China; Beijing Key Laboratory of Network System and Network Culture, Beijing University of Posts and Telecommunications, Beijing, 100876, China.
| | - Dong Su
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
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Lábár JL, Hajagos-Nagy K, Das PP, Gomez-Perez A, Radnóczi G. Simple ePDF: A Pair Distribution Function Method Based on Electron Diffraction Patterns to Reveal the Local Structure of Amorphous and Nanocrystalline Materials. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:3136. [PMID: 38133033 PMCID: PMC10745427 DOI: 10.3390/nano13243136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 12/10/2023] [Accepted: 12/12/2023] [Indexed: 12/23/2023]
Abstract
Amorphous, glassy or disordered materials play important roles in developing structural materials from metals or ceramics, devices from semiconductors or medicines from organic compounds. Their local structure is frequently similar to crystalline ones. A computer program is presented here that runs under the Windows operating system on a PC to extract pair distribution function (PDF) from electron diffraction in a transmission electron microscope (TEM). A polynomial correction reduces small systematic deviations from the expected average Q-dependence of scattering. Neighbor distance and coordination number measurements are supplemented by either measurement or enforcement of number density. Quantification of similarity is supported by calculation of Pearson's correlation coefficient and fingerprinting. A rough estimate of fractions in a mixture is computed by multiple least-square fitting using the PDFs from components of the mixture. PDF is also simulated from crystalline structural models (in addition to measured ones) to be used in libraries for fingerprinting or fraction estimation. Crystalline structure models for simulations are obtained from CIF files or str files of ProcessDiffraction. Data from inorganic samples exemplify usage. In contrast to previous free ePDF programs, our stand-alone program does not need a special software environment, which is a novelty. The program is available from the author upon request.
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Affiliation(s)
- János L. Lábár
- Thin Film Physics Laboratory, Institute of Technical Physics and Materials Science, HUN-REN Centre of Energy Research, Konkoly Thege M. út 29-33, H-1121 Budapest, Hungary; (K.H.-N.); (G.R.)
| | - Klára Hajagos-Nagy
- Thin Film Physics Laboratory, Institute of Technical Physics and Materials Science, HUN-REN Centre of Energy Research, Konkoly Thege M. út 29-33, H-1121 Budapest, Hungary; (K.H.-N.); (G.R.)
| | - Partha P. Das
- NanoMEGAS SPRL, Rue Èmile Claus 49 bte 9, 1050 Brussels, Belgium; (P.P.D.); (A.G.-P.)
| | - Alejandro Gomez-Perez
- NanoMEGAS SPRL, Rue Èmile Claus 49 bte 9, 1050 Brussels, Belgium; (P.P.D.); (A.G.-P.)
| | - György Radnóczi
- Thin Film Physics Laboratory, Institute of Technical Physics and Materials Science, HUN-REN Centre of Energy Research, Konkoly Thege M. út 29-33, H-1121 Budapest, Hungary; (K.H.-N.); (G.R.)
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Lábár JL, Pécz B, van Waveren A, Hallais G, Desvignes L, Chiodi F. Strain Measurement in Single Crystals by 4D-ED. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:1007. [PMID: 36985899 PMCID: PMC10054437 DOI: 10.3390/nano13061007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/01/2023] [Accepted: 03/06/2023] [Indexed: 06/18/2023]
Abstract
A new method is presented to measure strain over a large area of a single crystal. The 4D-ED data are collected by recording a 2D diffraction pattern at each position in the 2D area of the TEM lamella scanned by the electron beam of STEM. Data processing is completed with a new computer program (available free of charge) that runs under the Windows operating system. Previously published similar methods are either commercial or need special hardware (electron holography) or are based on HRTEM, which involves limitations with respect to the size of the field of view. All these limitations are overcome by our approach. The presence of defects results in small local changes in orientation that change the subset of experimentally available diffraction spots in the individual patterns. Our method is based on a new principle, namely fitting a lattice to (a subset of) measured diffraction spots to improve the precision of the measurement. Although a spot to be measured may be missing in some of the patterns even the missing spot can be precisely measured by the lattice determined from the available spots. Application is exemplified by heavily boron-doped silicon with intended usage as a low-temperature superconductor in qubits.
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Affiliation(s)
- János L. Lábár
- Thin Film Physics Laboratory, Institute of Technical Physics and Materials Science, Centre of Energy Research, Konkoly Thege M. u. 29-33, H-1121 Budapest, Hungary;
| | - Béla Pécz
- Thin Film Physics Laboratory, Institute of Technical Physics and Materials Science, Centre of Energy Research, Konkoly Thege M. u. 29-33, H-1121 Budapest, Hungary;
| | - Aiken van Waveren
- Centre de Nanosciences et de Nanotechnologies—C2N, Université Paris-Saclay, CNRS, 91120 Palaiseau, France (F.C.)
| | - Géraldine Hallais
- Centre de Nanosciences et de Nanotechnologies—C2N, Université Paris-Saclay, CNRS, 91120 Palaiseau, France (F.C.)
| | - Léonard Desvignes
- Centre de Nanosciences et de Nanotechnologies—C2N, Université Paris-Saclay, CNRS, 91120 Palaiseau, France (F.C.)
| | - Francesca Chiodi
- Centre de Nanosciences et de Nanotechnologies—C2N, Université Paris-Saclay, CNRS, 91120 Palaiseau, France (F.C.)
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Czigány Z, Kis VK. Acquisition and evaluation procedure to improve the accuracy of SAED. Microsc Res Tech 2023; 86:144-156. [PMID: 36069159 PMCID: PMC10087671 DOI: 10.1002/jemt.24229] [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: 03/25/2022] [Revised: 07/01/2022] [Accepted: 08/22/2022] [Indexed: 01/21/2023]
Abstract
The achievement of this work is that fine tuning of experimental and evaluation parameters can improve the absolute accuracy and reproducibility of selected area electron diffraction (SAED) to 0.1% without using internal standard. Due to the proposed procedure it was possible to reach a reproducibility better than 0.03% for camera length between sessions by careful control of specimen height and illumination conditions by monitoring lens currents. We applied a calibration specimen composed of nanocrystalline grains free of texture and providing narrow diffraction rings. Refinements of the centre of the diffraction pattern and corrections for elliptic ring distortions allowed for determining the ring diameters with an accuracy of 0.1%. We analyze the effect of different error sources and reason the achieved absolute accuracy of the measurement. Application of the proposed evaluation procedure is inevitable in case of multicomponent nanocomposites or textured materials and/or having close diffraction rings where application of automated procedures is limited. The achieved accuracy of 0.1% without internal standard is approaching that of routine laboratory XRD, and reduction of instrumental broadening due to the elaborated evaluation procedure allows for separation of close reflections, provides more reliable ring width and thus improved input parameters for further nanostructure analysis as demonstrated on dental enamel bioapatite.
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Affiliation(s)
- Zsolt Czigány
- Institute of Technical Physics and Materials Science, Centre for Energy Research, Budapest, Hungary
| | - Viktória Kovács Kis
- Institute of Technical Physics and Materials Science, Centre for Energy Research, Budapest, Hungary
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Khouchaf L, Boulahya K, Das PP, Nicolopoulos S, Kis VK, Lábár JL. Study of the Microstructure of Amorphous Silica Nanostructures Using High-Resolution Electron Microscopy, Electron Energy Loss Spectroscopy, X-ray Powder Diffraction, and Electron Pair Distribution Function. MATERIALS 2020; 13:ma13194393. [PMID: 33019776 PMCID: PMC7579662 DOI: 10.3390/ma13194393] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/22/2020] [Accepted: 09/27/2020] [Indexed: 11/25/2022]
Abstract
Silica has many industrial (i.e., glass formers) and scientific applications. The understanding and prediction of the interesting properties of such materials are dependent on the knowledge of detailed atomic structures. In this work, amorphous silica subjected to an accelerated alkali silica reaction (ASR) was recorded at different time intervals so as to follow the evolution of the structure by means of high-resolution transmission electron microscopy (HRTEM), electron energy loss spectroscopy (EELS), and electron pair distribution function (e-PDF), combined with X-ray powder diffraction (XRPD). An increase in the size of the amorphous silica nanostructures and nanopores was observed by HRTEM, which was accompanied by the possible formation of Si–OH surface species. All of the studied samples were found to be amorphous, as observed by HRTEM, a fact that was also confirmed by XRPD and e-PDF analysis. A broad diffuse peak observed in the XRPD pattern showed a shift toward higher angles following the higher reaction times of the ASR-treated material. A comparison of the EELS spectra revealed varying spectral features in the peak edges with different reaction times due to the interaction evolution between oxygen and the silicon and OH ions. Solid-state nuclear magnetic resonance (NMR) was also used to elucidate the silica nanostructures.
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Affiliation(s)
- Lahcen Khouchaf
- École Nationale Supérieure des Mines-Télécom de Lille-Douai Lille Douai, Lille Université, CEDEX, 59653 Villeneuve D’Ascq, France;
| | - Khalid Boulahya
- Departamento de Química Inorgánica, Facultad de Qúimicas, Universidad Complutense, 28040 Madrid, Spain;
| | - Partha Pratim Das
- Electron Crystallography Solutions SL, Calle Orense 8, 28020 Madrid, Spain
- NanoMEGAS SPRL, Blvd Edmond Machtens 79, B-1080 Brussels, Belgium
- Correspondence: (P.P.D.); (S.N.)
| | - Stavros Nicolopoulos
- NanoMEGAS SPRL, Blvd Edmond Machtens 79, B-1080 Brussels, Belgium
- Correspondence: (P.P.D.); (S.N.)
| | - Viktória Kovács Kis
- Institute of Technical Physics and Materials Science, Centre for Energy Research, 1121 Budapest, Hungary; (V.K.K.); (J.L.L.)
| | - János L. Lábár
- Institute of Technical Physics and Materials Science, Centre for Energy Research, 1121 Budapest, Hungary; (V.K.K.); (J.L.L.)
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Gorelik TE, Neder R, Terban MW, Lee Z, Mu X, Jung C, Jacob T, Kaiser U. Towards quantitative treatment of electron pair distribution function. ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE CRYSTAL ENGINEERING AND MATERIALS 2019; 75:532-549. [DOI: 10.1107/s205252061900670x] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 05/10/2019] [Indexed: 11/10/2022]
Abstract
The pair distribution function (PDF) is a versatile tool to describe the structure of disordered and amorphous materials. Electron PDF (ePDF) uses the advantage of strong scattering of electrons, thus allowing small volumes to be probed and providing unique information on structure variations at the nano-scale. The spectrum of ePDF applications is rather broad: from ceramic to metallic glasses and mineralogical to organic samples. The quantitative interpretation of ePDF relies on knowledge of how structural and instrumental effects contribute to the experimental data. Here, a broad overview is given on the development of ePDF as a structure analysis method and its applications to diverse materials. Then the physical meaning of the PDF is explained and its use is demonstrated with several examples. Special features of electron scattering regarding the PDF calculations are discussed. A quantitative approach to ePDF data treatment is demonstrated using different refinement software programs for a nanocrystalline anatase sample. Finally, a list of available software packages for ePDF calculation is provided.
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