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Buffat PA, Alexandrou I, Czyrska-Filemonowicz A. Composition and Element Distribution Mapping of γ' and γ″ Phases of Inconel 718 by High-Resolution Scanning Transmission Electron Microscopy and X-ray Energy-Dispersive Spectrometry. MATERIALS (BASEL, SWITZERLAND) 2024; 17:594. [PMID: 38591481 PMCID: PMC10856184 DOI: 10.3390/ma17030594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 01/15/2024] [Accepted: 01/18/2024] [Indexed: 04/10/2024]
Abstract
The main strengthening mechanism for Inconel 718 (IN718), a Ni-based superalloy, is precipitation hardening by γ' and γ″ particles. It is thus essential, for good alloy performance, that precipitates with the desired chemical composition have adequate size and dispersion. The distribution of the γ' and γ″ phases and their chemical composition were investigated in the nickel-based Inconel 718 superalloy by taking advantage of the new capabilities of scanning transmission electron microscopy and energy-dispersive X-ray spectrometry using a windowless multiple detector, a high-brightness Schottky electron gun, and a spherical aberration corrector in the illumination probe optics. A small routine was developed to deconvolute the respective compositions of γ' and γ″ nanoprecipitates embedded in the γ matrix. Keeping the electron probe current low enough-a few hundred pA-prevented excessive irradiation damage during the acquisition of element maps and brought their spatial resolution down to the atomic column level to track their element compositions. The present results agree with and complement atomic probe tomography observations and Thermo-Calc predictions from the literature. The presence of an Al enrichment at the γ'/γ″ interface-which may control the γ″ phase coarsening-is observed in the last row of Al-Nb-Ti columns along this interface. In addition, a few columns with similar composition changes are found randomly distributed in the γ' phase.
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Affiliation(s)
- Philippe A. Buffat
- Ecole Polytechnique Fédérale de Lausanne, Centre Interdisciplinaire de Microscopie Electronique, Ch. des Vioz 14, 1865 Les Diablerets, Switzerland
| | - Ioannis Alexandrou
- Thermo Fisher Scientific, De Schakel 2, 5651 GH Eindhoven, The Netherlands;
| | - Aleksandra Czyrska-Filemonowicz
- Faculty of Metals Engineering and Computer Science, Centre of Electron Microscopy for Materials Science, AGH University of Science and Technology, al. A. Mickiewicza 30, 30-059 Krakow, Poland;
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2
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Googasian JS, Skrabalak SE. Practical Considerations for Simulating the Plasmonic Properties of Metal Nanoparticles. ACS PHYSICAL CHEMISTRY AU 2023; 3:252-262. [PMID: 37249938 PMCID: PMC10214510 DOI: 10.1021/acsphyschemau.2c00064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 01/25/2023] [Accepted: 01/25/2023] [Indexed: 05/31/2023]
Abstract
Simulating the plasmonic properties of colloidally derived metal nanoparticles with accuracy to their experimentally observed measurements is challenging due to the many structural and compositional parameters that influence their scattering and absorption properties. Correlation between single nanoparticle scattering measurements and simulated spectra emphasize these strong structural and compositional relationships, providing insight into the design of plasmonic nanoparticles. This Perspective builds from this history to highlight how the structural features of models used in simulation methods such as those based on the Finite-Difference Time-Domain (FDTD) method and Discrete Dipole Approximation (DDA) are of critical consideration for correlation with experiment and ultimately prediction of new nanoparticle properties. High-level characterizations such as electron tomography are discussed as ways to advance the accuracy of models used in such simulations, allowing the plasmonic properties of structurally complex nanoparticles to be better understood. However, we also note that the field is far from bringing experiment and simulation into agreement for plasmonic nanoparticles with complex compositions, reflecting analytical challenges that inhibit accurate model generation. Potential directions for addressing these challenges are also presented.
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3
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Zhang Z, Lobato I, De Backer A, Van Aert S, Nellist P. Fast generation of calculated ADF-EDX scattering cross-sections under channelling conditions. Ultramicroscopy 2023; 246:113671. [PMID: 36621195 DOI: 10.1016/j.ultramic.2022.113671] [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: 07/15/2022] [Revised: 12/21/2022] [Accepted: 12/26/2022] [Indexed: 12/29/2022]
Abstract
Advanced materials often consist of multiple elements which are arranged in a complicated structure. Quantitative scanning transmission electron microscopy is useful to determine the composition and thickness of nanostructures at the atomic scale. However, significant difficulties remain to quantify mixed columns by comparing the resulting atomic resolution images and spectroscopy data with multislice simulations where dynamic scattering needs to be taken into account. The combination of the computationally intensive nature of these simulations and the enormous amount of possible mixed column configurations for a given composition indeed severely hamper the quantification process. To overcome these challenges, we here report the development of an incoherent non-linear method for the fast prediction of ADF-EDX scattering cross-sections of mixed columns under channelling conditions. We first explain the origin of the ADF and EDX incoherence from scattering physics suggesting a linear dependence between those two signals in the case of a high-angle ADF detector. Taking EDX as a perfect incoherent reference mode, we quantitatively examine the ADF longitudinal incoherence under different microscope conditions using multislice simulations. Based on incoherent imaging, the atomic lensing model previously developed for ADF is now expanded to EDX, which yields ADF-EDX scattering cross-section predictions in good agreement with multislice simulations for mixed columns in a core-shell nanoparticle and a high entropy alloy. The fast and accurate prediction of ADF-EDX scattering cross-sections opens up new opportunities to explore the wide range of ordering possibilities of heterogeneous materials with multiple elements.
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Affiliation(s)
- Zezhong Zhang
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, United Kingdom.
| | - Ivan Lobato
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Annick De Backer
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Sandra Van Aert
- Electron Microscopy for Materials Research (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
| | - Peter Nellist
- Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, United Kingdom.
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4
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De Backer A, Zhang Z, van den Bos KHW, Bladt E, Sánchez-Iglesias A, Liz-Marzán LM, Nellist PD, Bals S, Van Aert S. Element Specific Atom Counting at the Atomic Scale by Combining High Angle Annular Dark Field Scanning Transmission Electron Microscopy and Energy Dispersive X-ray Spectroscopy. SMALL METHODS 2022; 6:e2200875. [PMID: 36180399 DOI: 10.1002/smtd.202200875] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/29/2022] [Indexed: 06/16/2023]
Abstract
A new methodology is presented to count the number of atoms in multimetallic nanocrystals by combining energy dispersive X-ray spectroscopy (EDX) and high angle annular dark field scanning transmission electron microscopy (HAADF STEM). For this purpose, the existence of a linear relationship between the incoherent HAADF STEM and EDX images is exploited. Next to the number of atoms for each element in the atomic columns, the method also allows quantification of the error in the obtained number of atoms, which is of importance given the noisy nature of the acquired EDX signals. Using experimental images of an Au@Ag core-shell nanorod, it is demonstrated that 3D structural information can be extracted at the atomic scale. Furthermore, simulated data of an Au@Pt core-shell nanorod show the prospect to characterize heterogeneous nanostructures with adjacent atomic numbers.
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Affiliation(s)
- Annick De Backer
- EMAT, University of Antwerp, 2020, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, 2020, Antwerp, Belgium
| | - Zezhong Zhang
- EMAT, University of Antwerp, 2020, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, 2020, Antwerp, Belgium
| | - Karel H W van den Bos
- EMAT, University of Antwerp, 2020, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, 2020, Antwerp, Belgium
| | - Eva Bladt
- EMAT, University of Antwerp, 2020, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, 2020, Antwerp, Belgium
| | - Ana Sánchez-Iglesias
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), 20014, Donostia-San Sebastián, Spain
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), 20014, Donostia-San Sebastián, Spain
| | - Luis M Liz-Marzán
- CIC biomaGUNE, Basque Research and Technology Alliance (BRTA), 20014, Donostia-San Sebastián, Spain
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), 20014, Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48009, Bilbao, Spain
| | - Peter D Nellist
- Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK
| | - Sara Bals
- EMAT, University of Antwerp, 2020, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, 2020, Antwerp, Belgium
| | - Sandra Van Aert
- EMAT, University of Antwerp, 2020, Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, 2020, Antwerp, Belgium
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5
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Krisper R, Lammer J, Pivak Y, Fisslthaler E, Grogger W. The Performance of EDXS at Elevated Sample Temperatures Using a MEMS-Based In Situ TEM Heating System. Ultramicroscopy 2022; 234:113461. [PMID: 35121282 DOI: 10.1016/j.ultramic.2021.113461] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 12/15/2021] [Accepted: 12/29/2021] [Indexed: 11/20/2022]
Abstract
Since the development of MEMS heating holders, dynamic in-situ experiments at elevated temperatures may be complemented by X-ray spectrometry for chemical analysis. Although the amount of IR radiation is small when compared to furnace holders, the influence of IR radiation emitted from the heating device on the quality of the X-ray spectra is significant. In this work, we systematically examine the influence of infrared (IR) radiation generated by MEMS-based in situ heating systems (DENSsolutions single- and double-tilt holders) on the results and interpretation of energy-dispersive X-ray (EDX) spectra through simulation and measurement. Focal points of interest in this study are the influence of holder geometry, shadowing and orientation with respect to the different emission characteristics of IR and X-ray photons and their interaction with a side-entry and a multi-detector system. IR photons substantially contribute to count rates, dead time, electronic noise levels, energy resolution, and detection efficiency of semiconductor detectors. At higher sample temperatures, they ultimately limit the feasibility of EDXS for elemental characterization and especially the traceability of low-Z elements. This work provides a quantitative insight into the influence of all relevant parameters related to in situ heating experiments on the spectral quality. Bearing this in mind, we aim to provide a guide to optimizing in situ heating experiments with respect to chemical EDXS analysis.
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Affiliation(s)
- Robert Krisper
- Graz Centre for Electron Microscopy (ZFE), Austrian Cooperative Research (ACR), Steyrergasse 17, 8010 Graz, Austria; Institute of Electron Microscopy and Nanoanalysis (FELMI), Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria.
| | - Judith Lammer
- Graz Centre for Electron Microscopy (ZFE), Austrian Cooperative Research (ACR), Steyrergasse 17, 8010 Graz, Austria; Institute of Electron Microscopy and Nanoanalysis (FELMI), Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
| | - Yevheniy Pivak
- DENSsolutions, Informaticalaan 12, Delft, 2628ZD, The Netherlands
| | - Evelin Fisslthaler
- Graz Centre for Electron Microscopy (ZFE), Austrian Cooperative Research (ACR), Steyrergasse 17, 8010 Graz, Austria
| | - Werner Grogger
- Graz Centre for Electron Microscopy (ZFE), Austrian Cooperative Research (ACR), Steyrergasse 17, 8010 Graz, Austria; Institute of Electron Microscopy and Nanoanalysis (FELMI), Graz University of Technology, Steyrergasse 17, 8010 Graz, Austria
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6
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MacArthur KE, Yankovich AB, Béché A, Luysberg M, Brown HG, Findlay SD, Heggen M, Allen LJ. Optimizing Experimental Conditions for Accurate Quantitative Energy-Dispersive X-ray Analysis of Interfaces at the Atomic Scale. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2021; 27:1-15. [PMID: 33843542 DOI: 10.1017/s1431927621000246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The invention of silicon drift detectors has resulted in an unprecedented improvement in detection efficiency for energy-dispersive X-ray (EDX) spectroscopy in the scanning transmission electron microscope. The result is numerous beautiful atomic-scale maps, which provide insights into the internal structure of a variety of materials. However, the task still remains to understand exactly where the X-ray signal comes from and how accurately it can be quantified. Unfortunately, when crystals are aligned with a low-order zone axis parallel to the incident beam direction, as is necessary for atomic-resolution imaging, the electron beam channels. When the beam becomes localized in this way, the relationship between the concentration of a particular element and its spectroscopic X-ray signal is generally nonlinear. Here, we discuss the combined effect of both spatial integration and sample tilt for ameliorating the effects of channeling and improving the accuracy of EDX quantification. Both simulations and experimental results will be presented for a perovskite-based oxide interface. We examine how the scattering and spreading of the electron beam can lead to erroneous interpretation of interface compositions, and what approaches can be made to improve our understanding of the underlying atomic structure.
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Affiliation(s)
- Katherine E MacArthur
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, Jülich52425, Germany
| | - Andrew B Yankovich
- Department of Physics, Chalmers University of Technology, SE-412 96Gothenburg, Sweden
| | - Armand Béché
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, 2020Antwerp, Belgium
| | - Martina Luysberg
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, Jülich52425, Germany
| | - Hamish G Brown
- National Centre for Electron Microscopy, the Molecular Foundry, Lawrence Berkeley National Lab, Berkeley, CA94720, USA
| | - Scott D Findlay
- School of Physics and Astronomy, Monash University, Clayton, VIC3800, Australia
| | - Marc Heggen
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Peter Grünberg Institute, Forschungszentrum Jülich, Jülich52425, Germany
| | - Leslie J Allen
- School of Physics, University of Melbourne, Parkville, VIC3010, Australia
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7
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Numerical modeling of specimen geometry for quantitative energy dispersive X-ray spectroscopy. Ultramicroscopy 2018; 184:100-108. [DOI: 10.1016/j.ultramic.2017.08.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 08/21/2017] [Accepted: 08/29/2017] [Indexed: 11/16/2022]
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8
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Composition measurement in substitutionally disordered materials by atomic resolution energy dispersive X-ray spectroscopy in scanning transmission electron microscopy. Ultramicroscopy 2017; 176:52-62. [DOI: 10.1016/j.ultramic.2016.10.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 09/20/2016] [Accepted: 10/08/2016] [Indexed: 11/20/2022]
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9
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Bender H, Seidel F, Favia P, Richard O, Vandervorst W. X-ray absorption in pillar shaped transmission electron microscopy specimens. Ultramicroscopy 2017; 177:58-68. [PMID: 28292687 DOI: 10.1016/j.ultramic.2017.03.006] [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: 10/12/2016] [Revised: 01/11/2017] [Accepted: 03/05/2017] [Indexed: 11/25/2022]
Abstract
The dependence of the X-ray absorption on the position in a pillar shaped transmission electron microscopy specimen is modeled for X-ray analysis with single and multiple detector configurations and for different pillar orientations relative to the detectors. Universal curves, applicable to any pillar diameter, are derived for the relative intensities between weak and medium or strongly absorbed X-ray emission. For the configuration as used in 360° X-ray tomography, the absorption correction for weak and medium absorbed X-rays is shown to be nearly constant along the pillar diameter. Absorption effects in pillars are about a factor 3 less important than in planar specimens with thickness equal to the pillar diameter. A practical approach for the absorption correction in pillar shaped samples is proposed and its limitations discussed. The modeled absorption dependences are verified experimentally for pillars with HfO2 and SiGe stacks.
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Affiliation(s)
- H Bender
- Imec, Kapeldreef 75, 3001 Leuven, Belgium.
| | - F Seidel
- Imec, Kapeldreef 75, 3001 Leuven, Belgium
| | - P Favia
- Imec, Kapeldreef 75, 3001 Leuven, Belgium
| | - O Richard
- Imec, Kapeldreef 75, 3001 Leuven, Belgium
| | - W Vandervorst
- Imec, Kapeldreef 75, 3001 Leuven, Belgium; Instituut voor Kern- en Stralingsfysica, KU Leuven, 3001 Leuven, Belgium
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10
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Kraxner J, Schäfer M, Röschel O, Kothleitner G, Haberfehlner G, Paller M, Grogger W. Quantitative EDXS: Influence of geometry on a four detector system. Ultramicroscopy 2017; 172:30-39. [DOI: 10.1016/j.ultramic.2016.10.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 09/26/2016] [Accepted: 10/16/2016] [Indexed: 11/29/2022]
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11
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Improvement of effective solid angle using virtual-pivot holder and large EDS detector. Micron 2016; 93:52-56. [PMID: 27923156 DOI: 10.1016/j.micron.2016.11.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 11/23/2016] [Accepted: 11/23/2016] [Indexed: 11/20/2022]
Abstract
This paper describes the effective solid angle improvement achieved using a large-area silicon drift detector together with a virtual-pivot double-tilt specimen holder. The virtual-pivot mechanism enables various designs of specimen-retaining and can reduce the shadowing effect. Energy-dispersive X-ray spectra were measured and converted into effective solid angles using different types of specimen holders and specimens. The investigated shadowing-free mechanical system yielded effective solid angles approaching the nominal solid angle of 0.464sr. In addition, we have demonstrated the availability of the plastic (polyetheretherketone) specimen holder for low system noise.
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12
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Guo W, Sneed BT, Zhou L, Tang W, Kramer MJ, Cullen DA, Poplawsky JD. Correlative Energy-Dispersive X-Ray Spectroscopic Tomography and Atom Probe Tomography of the Phase Separation in an Alnico 8 Alloy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2016; 22:1251-1260. [PMID: 27998366 DOI: 10.1017/s1431927616012496] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Alnico alloys have long been used as strong permanent magnets because of their ferromagnetism and high coercivity. Understanding their structural details allows for better prediction of the resulting magnetic properties. However, quantitative three-dimensional characterization of the phase separation in these alloys is still challenged by the spatial quantification of nanoscale phases. Herein, we apply a dual tomography approach, where correlative scanning transmission electron microscopy (STEM) energy-dispersive X-ray spectroscopic (EDS) tomography and atom probe tomography (APT) are used to investigate the initial phase separation process of an alnico 8 alloy upon non-magnetic annealing. STEM-EDS tomography provides information on the morphology and volume fractions of Fe-Co-rich and Νi-Al-rich phases after spinodal decomposition in addition to quantitative information of the composition of a nanoscale volume. Subsequent analysis of a portion of the same specimen by APT offers quantitative chemical information of each phase at the sub-nanometer scale. Furthermore, APT reveals small, 2-4 nm Fe-rich α 1 phases that are nucleated in the Ni-rich α 2 matrix. From this information, we show that phase separation of the alnico 8 alloy consists of both spinodal decomposition and nucleation and growth processes. The complementary benefits and challenges associated with correlative STEM-EDS and APT are discussed.
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Affiliation(s)
- Wei Guo
- 1Oak Ridge National Laboratory,Center for Nanophase Materials Sciences,Oak Ridge,TN 37831,USA
| | - Brian T Sneed
- 1Oak Ridge National Laboratory,Center for Nanophase Materials Sciences,Oak Ridge,TN 37831,USA
| | - Lin Zhou
- 2Ames Laboratory, Division of Materials Science and Engineering,Ames,IA 50011,USA
| | - Wei Tang
- 2Ames Laboratory, Division of Materials Science and Engineering,Ames,IA 50011,USA
| | - Matthew J Kramer
- 2Ames Laboratory, Division of Materials Science and Engineering,Ames,IA 50011,USA
| | - David A Cullen
- 3Oak Ridge National Laboratory,Materials Science and Technology Division,Oak Ridge,TN 37831,USA
| | - Jonathan D Poplawsky
- 1Oak Ridge National Laboratory,Center for Nanophase Materials Sciences,Oak Ridge,TN 37831,USA
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13
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Aveyard R, Rieger B. Tilt series STEM simulation of a 25×25×25nm semiconductor with characteristic X-ray emission. Ultramicroscopy 2016; 171:96-103. [PMID: 27657648 DOI: 10.1016/j.ultramic.2016.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 09/05/2016] [Accepted: 09/11/2016] [Indexed: 11/19/2022]
Abstract
The detection and quantification of fabrication defects is vital to the ongoing miniaturization of integrated circuits. The atomic resolution of HAADF-STEM combined with the chemical sensitivity of EDS could provide the means by which this is achieved for the next generation of semiconductor devices. To realize this, however, a streamlined acquisition and analysis procedure must first be developed. Here, we report the simulation of a HAADF-STEM and EDS tilt-series dataset of a PMOS finFET device which will be used as a testbed for such a development. The methods used to calculate the data and the details of the specimen model are fully described here. The dataset consists of 179 projections in 2° increments with HAADF images and characteristic X-ray maps for each projection. This unusually large calculation has been made possible through the use of a national supercomputer and will be made available for the development and assessment of reconstruction and analysis procedures for this highly significant industrial application.
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Affiliation(s)
- R Aveyard
- Department of Imaging Physics, Delft University of Technology, 2628CJ Delft, The Netherlands
| | - B Rieger
- Department of Imaging Physics, Delft University of Technology, 2628CJ Delft, The Netherlands.
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14
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Influence of experimental conditions on atom column visibility in energy dispersive X-ray spectroscopy. Ultramicroscopy 2016; 171:1-7. [PMID: 27584051 DOI: 10.1016/j.ultramic.2016.08.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 08/08/2016] [Accepted: 08/18/2016] [Indexed: 11/21/2022]
Abstract
Here we report the influence of key experimental parameters on atomically resolved energy dispersive X-ray spectroscopy (EDX). In particular, we examine the role of the probe forming convergence semi-angle, sample thickness, lattice spacing, and dwell/collection time. We show that an optimum specimen-dependent probe forming convergence angle exists to maximize the signal-to-noise ratio of the atomically resolved signal in EDX mapping. Furthermore, we highlight that it can be important to select an appropriate dwell time to efficiently process the X-ray signal. These practical considerations provide insight for experimental parameters in atomic resolution energy dispersive X-ray analysis.
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15
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Chen Z, Weyland M, Sang X, Xu W, Dycus J, LeBeau J, D'Alfonso A, Allen L, Findlay S. Quantitative atomic resolution elemental mapping via absolute-scale energy dispersive X-ray spectroscopy. Ultramicroscopy 2016; 168:7-16. [DOI: 10.1016/j.ultramic.2016.05.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 05/05/2016] [Accepted: 05/21/2016] [Indexed: 11/26/2022]
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