1
|
Holm JD, Mansfield E. Transmission electron imaging and diffraction of asbestos fibers in a scanning electron microscope. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2024; 16:4570-4581. [PMID: 38912607 DOI: 10.1039/d4ay00555d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/25/2024]
Abstract
Test protocols for airborne clearance of asbestos abatement sites define the collection, imaging and quantification of asbestos with transmission electron microscopy (TEM). Since those protocols were developed 35 years ago, scanning electron microscope (SEM) capabilities have significantly improved and expanded, with improvements in image spatial resolution, elemental analysis, and transmission electron diffraction capabilities. This contribution demonstrates transmission electron imaging and diffraction using NIST Asbestos Standard Reference Materials and a conventional SEM to provide comparable identification and quantification capabilities in the SEM as the current regulatory methods based on TEM techniques. In particular, we demonstrate that the 0.53 nm layer line spacing that is characteristic of asbestos can be quantified using different detection methods, and that other identifying diffraction signatures of chrysotile are readily obtained. The results demonstrate a viable alternative to the current TEM-based methods for asbestos identification and classification.
Collapse
Affiliation(s)
- Jason D Holm
- National Institute of Standards and Technology, Applied Chemicals and Materials Division, Boulder, CO, 80305, USA.
| | - Elisabeth Mansfield
- National Institute of Standards and Technology, Applied Chemicals and Materials Division, Boulder, CO, 80305, USA.
| |
Collapse
|
2
|
Moradifar P, Liu Y, Shi J, Siukola Thurston ML, Utzat H, van Driel TB, Lindenberg AM, Dionne JA. Accelerating Quantum Materials Development with Advances in Transmission Electron Microscopy. Chem Rev 2023. [PMID: 37979189 DOI: 10.1021/acs.chemrev.2c00917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2023]
Abstract
Quantum materials are driving a technology revolution in sensing, communication, and computing, while simultaneously testing many core theories of the past century. Materials such as topological insulators, complex oxides, superconductors, quantum dots, color center-hosting semiconductors, and other types of strongly correlated materials can exhibit exotic properties such as edge conductivity, multiferroicity, magnetoresistance, superconductivity, single photon emission, and optical-spin locking. These emergent properties arise and depend strongly on the material's detailed atomic-scale structure, including atomic defects, dopants, and lattice stacking. In this review, we describe how progress in the field of electron microscopy (EM), including in situ and in operando EM, can accelerate advances in quantum materials and quantum excitations. We begin by describing fundamental EM principles and operation modes. We then discuss various EM methods such as (i) EM spectroscopies, including electron energy loss spectroscopy (EELS), cathodoluminescence (CL), and electron energy gain spectroscopy (EEGS); (ii) four-dimensional scanning transmission electron microscopy (4D-STEM); (iii) dynamic and ultrafast EM (UEM); (iv) complementary ultrafast spectroscopies (UED, XFEL); and (v) atomic electron tomography (AET). We describe how these methods could inform structure-function relations in quantum materials down to the picometer scale and femtosecond time resolution, and how they enable precision positioning of atomic defects and high-resolution manipulation of quantum materials. For each method, we also describe existing limitations to solve open quantum mechanical questions, and how they might be addressed to accelerate progress. Among numerous notable results, our review highlights how EM is enabling identification of the 3D structure of quantum defects; measuring reversible and metastable dynamics of quantum excitations; mapping exciton states and single photon emission; measuring nanoscale thermal transport and coupled excitation dynamics; and measuring the internal electric field and charge density distribution of quantum heterointerfaces- all at the quantum materials' intrinsic atomic and near atomic-length scale. We conclude by describing open challenges for the future, including achieving stable sample holders for ultralow temperature (below 10K) atomic-scale spatial resolution, stable spectrometers that enable meV energy resolution, and high-resolution, dynamic mapping of magnetic and spin fields. With atomic manipulation and ultrafast characterization enabled by EM, quantum materials will be poised to integrate into many of the sustainable and energy-efficient technologies needed for the 21st century.
Collapse
Affiliation(s)
- Parivash Moradifar
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
| | - Yin Liu
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Jiaojian Shi
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road MS69, Menlo Park, California 94025, United States
| | | | - Hendrik Utzat
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
| | - Tim B van Driel
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Aaron M Lindenberg
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road MS69, Menlo Park, California 94025, United States
| | - Jennifer A Dionne
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- Department of Radiology, Stanford University, Stanford, California 94305, United States
| |
Collapse
|
3
|
Snyder RM, Juelsholt M, Kalha C, Holm J, Mansfield E, Lee TL, Thakur PK, Riaz AA, Moss B, Regoutz A, Birkel CS. Detailed Analysis of the Synthesis and Structure of MAX Phase (Mo 0.75V 0.25) 5AlC 4 and Its MXene Sibling (Mo 0.75V 0.25) 5C 4. ACS NANO 2023. [PMID: 37368981 DOI: 10.1021/acsnano.3c03395] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
MAX phases with the general formula Mn+1AXn are layered carbides, nitrides, and carbonitrides with varying stacking sequence of layers of M6X octahedra and the A element depending on n. While "211" MAXphases (n = 1) are very common, MAX phases with higher n, especially n ≥ 3, have hardly been prepared. This work addresses open questions regarding the synthesis conditions, structure, and chemical composition of the "514" MAX phase. In contrast to literature reports, no oxide is needed to form the MAX phase, yet multiple heating steps at 1,600 °C are required. Using high-resolution X-ray diffraction, the structure of (Mo1-xVx)5AlC4 is thoroughly investigated, and Rietveld refinement suggests P-6c2 as the most fitting space group. SEM/EDS and XPS show that the chemical composition of the MAX phase is (Mo0.75V0.25)5AlC4. It was also exfoliated into its MXene sibling (Mo0.75V0.25)5C4 using two different techniques (using HF and an HF/HCl mixture) that lead to different surface terminations as shown by XPS/HAXPES measurements. Initial investigations of the electrocatalytic properties of both MXene versions show that, depending on the etchant, (Mo0.75V0.25)5C4 can reduce hydrogen at 10 mA cm-2 with an overpotential of 166 mV (HF only) or 425 mV (HF/HCl) after cycling the samples, which makes them a potential candidate as an HER catalyst.
Collapse
Affiliation(s)
- Rose M Snyder
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85281, United States
| | - Mikkel Juelsholt
- Department of Materials, University of Oxford, Oxford, OX1 3PH, U.K
| | - Curran Kalha
- Department of Chemistry, University College London, London, WC1H 0AJ, U.K
| | - Jason Holm
- Applied Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, Colorado 80305, United States
| | - Elisabeth Mansfield
- Applied Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, Colorado 80305, United States
| | - Tien-Lin Lee
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, U.K
| | - Pardeep K Thakur
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, U.K
| | - Aysha A Riaz
- Department of Chemistry, University College London, London, WC1H 0AJ, U.K
| | - Benjamin Moss
- Department of Chemistry, Molecular Science Research Hub, White City Campus, Imperial College London, London W12 0BZ, U.K
| | - Anna Regoutz
- Department of Chemistry, University College London, London, WC1H 0AJ, U.K
| | - Christina S Birkel
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85281, United States
- Department of Chemistry and Biochemistry, Technische Universitaet Darmstadt, 64287 Darmstadt, Germany
| |
Collapse
|
4
|
Ham J, Lim J, Hong S, Lee WC. Spin Coating Promotes the Epitaxial Growth of AgCN Microwires on 2D Materials. ACS NANO 2022; 16:20521-20532. [PMID: 36475627 DOI: 10.1021/acsnano.2c06963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Epitaxial growth of inorganic crystals on 2D materials is expected to greatly advance nanodevices and nanocomposites. However, because pristine surfaces of 2D materials are chemically inert, it is difficult to grow inorganic crystals epitaxially on 2D materials. Previously, successful results were achieved only by vapor-phase deposition at high temperature, and solution-based deposition including spin coating made the epitaxial growth unaligned, sparse, or nonuniform on 2D materials. Here, we show that solvent-controlled spin coating can uniformly deposit a dense layer of epitaxial AgCN microwires onto various 2D materials. Adding ethanol to an aqueous AgCN solution facilitates uniform formation of the thin supersaturated solution layer during spin coating, which promotes heterogeneous crystal nucleation on 2D material surfaces over homogeneous nucleation in the bulk solution. Microscopic analysis confirms highly aligned, uniform, and dense growth of epitaxial AgCN microwires on graphene, MoS2, hBN, WS2, and WSe2. The epitaxial microwires, which are optically observable and chemically removable, enable crystallographic mapping of grains in millimeter-sized polycrystalline graphene as well as precise control of twist angles (<∼1°) in van der Waals heterostructures. In addition to these practical applications, our study demonstrates the potential of 2D materials as epitaxial templates even in spin coating of inorganic crystals.
Collapse
Affiliation(s)
- Jimin Ham
- Department of Mechanical Engineering, BK21FOUR ERICA-ACE Center, Hanyang University, Ansan, Gyeonggi15588, Republic of Korea
| | - Jaemook Lim
- Department of Mechanical Engineering, BK21FOUR ERICA-ACE Center, Hanyang University, Ansan, Gyeonggi15588, Republic of Korea
| | - Sukjoon Hong
- Department of Mechanical Engineering, BK21FOUR ERICA-ACE Center, Hanyang University, Ansan, Gyeonggi15588, Republic of Korea
| | - Won Chul Lee
- Department of Mechanical Engineering, BK21FOUR ERICA-ACE Center, Hanyang University, Ansan, Gyeonggi15588, Republic of Korea
| |
Collapse
|
5
|
Londoño-Calderon A, Dhall R, Ophus C, Schneider M, Wang Y, Dervishi E, Kang HS, Lee CH, Yoo J, Pettes MT. Visualizing Grain Statistics in MOCVD WSe 2 through Four-Dimensional Scanning Transmission Electron Microscopy. NANO LETTERS 2022; 22:2578-2585. [PMID: 35143727 DOI: 10.1021/acs.nanolett.1c04315] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Using four-dimensional scanning transmission electron microscopy, we demonstrate a method to visualize grains and grain boundaries in WSe2 grown by metal organic chemical vapor deposition (MOCVD) directly onto silicon dioxide. Despite the chemical purity and uniform thickness and texture of the MOCVD-grown WSe2, we observe a high density of small grains that corresponds with the overall selenium deficiency we measure through ion beam analysis. Moreover, reconstruction of grain information permits the creation of orientation maps that demonstrate the nucleation mechanism for new layers-triangular domains with the same orientation as the layer underneath induces a tensile strain increasing the lattice parameter at these sites.
Collapse
Affiliation(s)
- Alejandra Londoño-Calderon
- Center for Integrated Nanotechnologies (CINT), Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Rohan Dhall
- National Center for Electron Microscopy (NCEM), Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Colin Ophus
- National Center for Electron Microscopy (NCEM), Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Matthew Schneider
- Materials Science in Radiation and Dynamics Extremes (MST-8), Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Yongqiang Wang
- Center for Integrated Nanotechnologies (CINT), Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
- Materials Science in Radiation and Dynamics Extremes (MST-8), Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Enkeleda Dervishi
- Electrochemistry and Corrosion Team, Sigma Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Hee Seong Kang
- KU-KIST Graduate School of Converging Science and Technology & Department of Integrative Energy Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Chul-Ho Lee
- KU-KIST Graduate School of Converging Science and Technology & Department of Integrative Energy Engineering, Korea University, Seoul, 02841, Republic of Korea
- Advanced Materials Research Division, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Jinkyoung Yoo
- Center for Integrated Nanotechnologies (CINT), Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Michael T Pettes
- Center for Integrated Nanotechnologies (CINT), Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| |
Collapse
|
6
|
Slouf M, Skoupy R, Pavlova E, Krzyzanek V. High Resolution Powder Electron Diffraction in Scanning Electron Microscopy. MATERIALS 2021; 14:ma14247550. [PMID: 34947146 PMCID: PMC8708290 DOI: 10.3390/ma14247550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/03/2021] [Accepted: 12/07/2021] [Indexed: 11/16/2022]
Abstract
A modern scanning electron microscope equipped with a pixelated detector of transmitted electrons can record a four-dimensional (4D) dataset containing a two-dimensional (2D) array of 2D nanobeam electron diffraction patterns; this is known as a four-dimensional scanning transmission electron microscopy (4D-STEM). In this work, we introduce a new version of our method called 4D-STEM/PNBD (powder nanobeam diffraction), which yields high-resolution powder diffractograms, whose quality is fully comparable to standard TEM/SAED (selected-area electron diffraction) patterns. Our method converts a complex 4D-STEM dataset measured on a nanocrystalline material to a single 2D powder electron diffractogram, which is easy to process with standard software. The original version of 4D-STEM/PNBD method, which suffered from low resolution, was improved in three important areas: (i) an optimized data collection protocol enables the experimental determination of the point spread function (PSF) of the primary electron beam, (ii) an improved data processing combines an entropy-based filtering of the whole dataset with a PSF-deconvolution of the individual 2D diffractograms and (iii) completely re-written software automates all calculations and requires just a minimal user input. The new method was applied to Au, TbF3 and TiO2 nanocrystals and the resolution of the 4D-STEM/PNBD diffractograms was even slightly better than that of TEM/SAED.
Collapse
Affiliation(s)
- Miroslav Slouf
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovsky Sq. 2, 16206 Prague, Czech Republic;
- Correspondence: (M.S.); (V.K.)
| | - Radim Skoupy
- Institute of Scientific Instruments of the Czech Academy of Sciences, Kralovopolska 147, 61264 Brno, Czech Republic;
| | - Ewa Pavlova
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovsky Sq. 2, 16206 Prague, Czech Republic;
| | - Vladislav Krzyzanek
- Institute of Scientific Instruments of the Czech Academy of Sciences, Kralovopolska 147, 61264 Brno, Czech Republic;
- Correspondence: (M.S.); (V.K.)
| |
Collapse
|
7
|
Slouf M, Skoupy R, Pavlova E, Krzyzanek V. Powder Nano-Beam Diffraction in Scanning Electron Microscope: Fast and Simple Method for Analysis of Nanoparticle Crystal Structure. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:962. [PMID: 33918700 PMCID: PMC8070269 DOI: 10.3390/nano11040962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 03/31/2021] [Accepted: 04/06/2021] [Indexed: 02/05/2023]
Abstract
We introduce a novel scanning electron microscopy (SEM) method which yields powder electron diffraction patterns. The only requirement is that the SEM microscope must be equipped with a pixelated detector of transmitted electrons. The pixelated detectors for SEM have been commercialized recently. They can be used routinely to collect a high number of electron diffraction patterns from individual nanocrystals and/or locations (this is called four-dimensional scanning transmission electron microscopy (4D-STEM), as we obtain two-dimensional (2D) information for each pixel of the 2D scanning array). Nevertheless, the individual 4D-STEM diffractograms are difficult to analyze due to the random orientation of nanocrystalline material. In our method, all individual diffractograms (showing randomly oriented diffraction spots from a few nanocrystals) are combined into one composite diffraction pattern (showing diffraction rings typical of polycrystalline/powder materials). The final powder diffraction pattern can be analyzed by means of standard programs for TEM/SAED (Selected-Area Electron Diffraction). We called our new method 4D-STEM/PNBD (Powder NanoBeam Diffraction) and applied it to three different systems: Au nano-islands (well diffracting nanocrystals with size ~20 nm), small TbF3 nanocrystals (size < 5 nm), and large NaYF4 nanocrystals (size > 100 nm). In all three cases, the STEM/PNBD results were comparable to those obtained from TEM/SAED. Therefore, the 4D-STEM/PNBD method enables fast and simple analysis of nanocrystalline materials, which opens quite new possibilities in the field of SEM.
Collapse
Affiliation(s)
- Miroslav Slouf
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic;
| | - Radim Skoupy
- Institute of Scientific Instruments of the Czech Academy of Sciences, Kralovopolska 147, 612 64 Brno, Czech Republic;
| | - Ewa Pavlova
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic;
| | - Vladislav Krzyzanek
- Institute of Scientific Instruments of the Czech Academy of Sciences, Kralovopolska 147, 612 64 Brno, Czech Republic;
| |
Collapse
|