1
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Iwashimizu C, Haruta M, Nemoto T, Kurata H. Different atomic contrasts in HAADF images and EELS maps of rutile TiO2. Microscopy (Oxf) 2023; 72:353-360. [PMID: 36440709 DOI: 10.1093/jmicro/dfac067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/21/2022] [Accepted: 11/27/2022] [Indexed: 08/05/2023] Open
Abstract
High-angle annular dark-field (HAADF) imaging and elemental mapping at the atomic scale by scanning transmission electron microscopy (STEM) combined with electron energy-loss spectroscopy (EELS) are widely used for material characterization, in which quantitative understanding of the contrast of the image is required. Here, we report an unexpected image contrast in the elemental mapping of rutile TiO2, where the Ti L2,3 map shows an anisotropic elliptical shape that extends along the long axis in the octahedral structure, while the atomic contrast of Ti columns in the HAADF image is almost circular. Multi-slice simulation reveals that unique electron channeling related to the rutile structure and the difference of the potentials between HAADF and EELS cause the different atomic contrasts in the two images.
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Affiliation(s)
- Chisaki Iwashimizu
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Mitsutaka Haruta
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Takashi Nemoto
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Hiroki Kurata
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
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2
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Yamashita S, Inatomi Y, Inaba Y, Tanabe M, Nishi T, Kudo Y. Atomic-Scale Dynamics at Solid-Liquid Nanointerfaces Induced by Electron-Beam Irradiation. NANO LETTERS 2022; 22:10073-10079. [PMID: 36512517 DOI: 10.1021/acs.nanolett.2c03838] [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
We report electron-beam induced dynamics at PbS-Pb solid-liquid interfaces. We fabricated PbS-Pb solid-liquid nanointerfaces by heating PbS nanocrystals under vacuum to observe the entire process of structural evolution at the atomic scale. We investigated the dynamics using time-resolved high-angle annular dark-field imaging. Electron-beam irradiation caused layer-by-layer dissolution of PbS at the interface, resulting in the formation of the Pb nanodroplet. Ordered liquid layers were observed adjacent to the interface even under continuous electron-beam irradiation and followed the movement of the interface. Instantaneous epitaxial growth of PbS was observed as a reverse process of the dissolution. The resultant Pb nanodroplet provides indisputable evidence for selective sputtering of sulfur atoms via electron-beam irradiation. This paper demonstrates atomic resolution in situ observations of selective and complete sputtering. The observed dynamics can be explained by the intermittent phase transition via nonequilibrium states of the solid-liquid nanointerface triggered by selective sputtering.
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Affiliation(s)
- Shunsuke Yamashita
- R&D Center, Sony Group Corporation, 4-14-1 Asahi-cho, Atsugi, Kanagawa243-0014, Japan
| | - Yuya Inatomi
- R&D Center, Sony Group Corporation, 4-14-1 Asahi-cho, Atsugi, Kanagawa243-0014, Japan
| | - Yuta Inaba
- R&D Center, Sony Group Corporation, 4-14-1 Asahi-cho, Atsugi, Kanagawa243-0014, Japan
| | - Mamoru Tanabe
- R&D Center, Sony Group Corporation, 4-14-1 Asahi-cho, Atsugi, Kanagawa243-0014, Japan
| | - Toshio Nishi
- R&D Center, Sony Group Corporation, 4-14-1 Asahi-cho, Atsugi, Kanagawa243-0014, Japan
| | - Yoshihiro Kudo
- R&D Center, Sony Group Corporation, 4-14-1 Asahi-cho, Atsugi, Kanagawa243-0014, Japan
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3
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Hayashida M, Malac M. High-Energy Electron Scattering in Thick Samples Evaluated by Bright-Field Transmission Electron Microscopy, Energy-Filtering Transmission Electron Microscopy, and Electron Tomography. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2022; 28:1-13. [PMID: 35343421 DOI: 10.1017/s1431927622000472] [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
Energy-filtering transmission electron microscopy (TEM) and bright-field TEM can be used to extract local sample thickness $t$ and to generate two-dimensional sample thickness maps. Electron tomography can be used to accurately verify the local $t$. The relations of log-ratio of zero-loss filtered energy-filtering TEM beam intensity ($I_{{\rm ZLP}}$) and unfiltered beam intensity ($I_{\rm u}$) versus sample thickness $t$ were measured for five values of collection angle in a microscope equipped with an energy filter. Furthermore, log-ratio of the incident (primary) beam intensity ($I_{\rm p}$) and the transmitted beam $I_{{\rm tr}}$ versus $t$ in bright-field TEM was measured utilizing a camera before the energy filter. The measurements were performed on a multilayer sample containing eight materials and thickness $t$ up to 800 nm. Local thickness $t$ was verified by electron tomography. The following results are reported:• The maximum thickness $t_{{\rm max}}$ yielding a linear relation of log-ratio, $\ln ( {I_{\rm u}}/{I_{{\rm ZLP}}})$ and $\ln ( {I_{\rm p}}/{I_{{\rm tr}}} )$, versus $t$.• Inelastic mean free path ($\lambda _{{\rm in}}$) for five values of collection angle.• Total mean free path ($\lambda _{{\rm total}}$) of electrons excluded by an angle-limiting aperture.• $\lambda _{{\rm in}}$ and $\lambda _{{\rm total}}$ are evaluated for the eight materials with atomic number from $\approx$10 to 79.The results can be utilized as a guide for upper limit of $t$ evaluation in energy-filtering TEM and bright-field TEM and for optimizing electron tomography experiments.
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Affiliation(s)
- Misa Hayashida
- Nanotechnology Research Centre, National Research Council, Edmonton, ABT6G 2M9, Canada
| | - Marek Malac
- Nanotechnology Research Centre, National Research Council, Edmonton, ABT6G 2M9, Canada
- Department of Physics, University of Alberta, Edmonton, ABT6G 2E1, Canada
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4
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Zhang H, Jimbo Y, Niwata A, Ikeda A, Yasuhara A, Ovidiu C, Kimoto K, Kasaya T, Miyazaki HT, Tsujii N, Wang H, Yamauchi Y, Fujita D, Kitamura SI, Manabe H. High-endurance micro-engineered LaB 6 nanowire electron source for high-resolution electron microscopy. NATURE NANOTECHNOLOGY 2022; 17:21-26. [PMID: 34750559 DOI: 10.1038/s41565-021-00999-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 09/06/2021] [Indexed: 06/13/2023]
Abstract
The size tunability and chemical versatility of nanostructures enable electron sources of high brightness and temporal coherence, both of which are important characteristics for high-resolution electron microscopy1-3. Despite intensive research efforts in the field, so far, only conventional field emitters based on a bulk tungsten (W) needle have been able to yield atomic-resolution images. The absence of viable alternatives is in part caused by insufficient fabrication precision for nanostructured sources, which require an alignment precision of subdegree angular deviation of a nanometre-sized emission area with the macroscopic emitter axis4. To overcome this challenge, in this work we micro-engineered a LaB6 nanowire-based electron source that emitted a highly collimated electron beam with good lateral and angular alignment. We integrated a passive collimator structure into the support needle tip for the LaB6 nanowire emitter. The collimator formed an axially symmetric electric field around the emission tip of the nanowire. Furthermore, by means of micromanipulation, the support needle tip was bent to align the emitted electron beam with the emitter axis. After installation in an aberration-corrected transmission electron microscope, we characterized the performance of the electron source in a vacuum of 10-8 Pa and achieved atomic resolution in both broad-beam and probe-forming modes at 60 kV beam energy. The natural, unmonochromated 0.20 eV electron energy loss spectroscopy resolution, 20% probe-forming efficiency and 0.4% probe current peak-to-peak noise ratio paired with modest vacuum requirements make the LaB6 nanowire-based electron source an attractive alternative to the standard W-based sources for low-cost electron beam instruments.
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Affiliation(s)
- Han Zhang
- Research Center for Advanced Material Characterization, National Institute for Materials Science, Tsukuba, Japan.
| | - Yu Jimbo
- JEOL Ltd, Akishima, Tokyo, Japan
| | | | | | | | - Cretu Ovidiu
- Research Center for Advanced Material Characterization, National Institute for Materials Science, Tsukuba, Japan
| | - Koji Kimoto
- Research Center for Advanced Material Characterization, National Institute for Materials Science, Tsukuba, Japan
| | - Takeshi Kasaya
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Hideki T Miyazaki
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Naohito Tsujii
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Hongxin Wang
- Research Center for Advanced Material Characterization, National Institute for Materials Science, Tsukuba, Japan
| | - Yasushi Yamauchi
- Research Center for Advanced Material Characterization, National Institute for Materials Science, Tsukuba, Japan
| | - Daisuke Fujita
- Research Center for Advanced Material Characterization, National Institute for Materials Science, Tsukuba, Japan
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5
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Akita I, Ishida Y, Yonezawa T. Atomic-Scale Imaging of a Free-Standing Monolayer Clay Mineral Nanosheet Using Scanning Transmission Electron Microscopy. J Phys Chem Lett 2020; 11:3357-3361. [PMID: 32248680 DOI: 10.1021/acs.jpclett.0c00758] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Although aberration-corrected scanning transmission electron microscope (STEM) enables the atomic-scale visualization of ultrathin 2D materials such as graphene, imaging of electron-beam sensitive 2D materials with structural complexity is an intricate problem. We here report the first atomic-scale imaging of a free-standing monolayer clay mineral nanosheet via the annular dark field (ADF) STEM. The monolayer clay nanosheet was stably observed under optimal conditions, and we confirmed that the hexagonal contrast pattern with a pore of ∼4 Å corresponds to the atomic structure of clay mineral that consisted of adjacent Si, Al, Mg, and O atoms by comparison with simulations. The findings offer the usefulness of ADF-STEM techniques for the atomic scale imaging of clay minerals and various 2D materials having electron-beam sensitivity and structural complexity than few-atom-thick graphene analogues.
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Affiliation(s)
- Ikumi Akita
- Division of Materials Science and Engineering, Faculty of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan
| | - Yohei Ishida
- Division of Materials Science and Engineering, Faculty of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan
| | - Tetsu Yonezawa
- Division of Materials Science and Engineering, Faculty of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan
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6
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Blom DA, Vogt T. Probing Compositional Order in Atomic Columns: STEM Simulations Beyond the Virtual Crystal Approximation. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2020; 26:46-52. [PMID: 31839023 DOI: 10.1017/s1431927619015198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Taking advantage of recent advances in parallel computing, we studied compositional disorder along metal-oxygen atomic columns in a complex Mo,V-oxide bronze using multislice frozen-phonon calculations. Commonly, the virtual crystal approximation (VCA) is used to model compositional disorder at crystallographic sites in a unit cell for a number of different theoretical and experimental techniques. In the VCA, a weighted linear sum of atomic properties is used to approximate the model structure. When using the VCA, the extracted V content of Mo,V-O columns from experimental high-angle annular dark-field (HAADF) images will be about half the V content estimated from simulations, considering the distinct cation ordering. This discrepancy is larger than the spread of HAADF signals of different configurational orders at a given V concentration, which can be up to 20%. Certain "isophilic" atomic arrangements along the column can be distinguished from more random ones using HAADF-STEM imaging. The trends and ratios of the simulated intensity spreads due to different compositional ordering along 11 M-O columns along the c-axis of the Mo,V oxide bronze qualitatively match those observed in experimental HAADF-STEM data. Instrumental and sample-based noise adds to the variability but does not significantly distort the relative ratios of column intensity variation. We observed that we only required seven random configurations to represent the intensity variations along columns.
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Affiliation(s)
- Douglas A Blom
- Department of Chemical Engineering and NanoCenter, University of South Carolina, 715 Sumter St., Room 001, Columbia, SC29208, USA
| | - Thomas Vogt
- Department of Chemistry and Biochemistry and NanoCenter, University of South Carolina, 631 Sumter St., Columbia, SC29208, USA
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7
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Akita I, Ishida Y, Yonezawa T. Distinctive stability of a free-standing monolayer clay mineral nanosheet via transmission electron microscopy. Phys Chem Chem Phys 2020; 22:25095-25102. [DOI: 10.1039/d0cp04659k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The distinctive stability of the monolayer clay mineral demonstrated by electron diffraction.
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Affiliation(s)
- Ikumi Akita
- Division of Materials Science and Engineering
- Faculty of Engineering
- Hokkaido University
- Sapporo
- Japan
| | - Yohei Ishida
- Division of Materials Science and Engineering
- Faculty of Engineering
- Hokkaido University
- Sapporo
- Japan
| | - Tetsu Yonezawa
- Division of Materials Science and Engineering
- Faculty of Engineering
- Hokkaido University
- Sapporo
- Japan
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8
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Kimoto K, Kikkawa J, Cretu O, Yanagisawa Y, Ishizuka K. K-4 Current Status of Crystal Structure Analysis using Scanning Transmission Electron Microscopy. Microscopy (Oxf) 2019. [DOI: 10.1093/jmicro/dfz042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Koji Kimoto
- National Institute for Materials Science (NIMS), Tsukuba, Japan
| | - Jun Kikkawa
- National Institute for Materials Science (NIMS), Tsukuba, Japan
| | - Ovidiu Cretu
- National Institute for Materials Science (NIMS), Tsukuba, Japan
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9
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Zhao X, Ning S, Fu W, Pennycook SJ, Loh KP. Differentiating Polymorphs in Molybdenum Disulfide via Electron Microscopy. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1802397. [PMID: 30160317 DOI: 10.1002/adma.201802397] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 05/31/2018] [Indexed: 06/08/2023]
Abstract
The presence of rich polymorphs and stacking polytypes in molybdenum disulfide (MoS2 ) endows it with a diverse range of electrical, catalytic, optical, and magnetic properties. This has stimulated a lot of interest in the unique properties associated with each polymorph. Most techniques used for polymorph identification in MoS2 are macroscopic techniques that sample averaged properties due to their limited spatial resolution. A reliable way of differentiating the atomic structure of different polymorphs is needed in order to understand their growth dynamics and establish the correlation between structure and properties. Herein, the use of electron microscopy for identifying the atomic structures of several important polymorphs in MoS2 , some of which are the subjects of mistaken assignment in the literature, is discussed. In particular, scanning transmission electron microscopy-annular dark field imaging has emerged as the most effective and reliable approach for identifying the different phases in MoS2 and other 2D materials because its images can be directly correlated to the atomic structures. Examples of the identification of polymorphs grown under different conditions in molecular beam epitaxy or chemical vapor deposition, for example, 3R, 1T, 1T'-phases, and 1T'-edges, are presented, including their atomic structures, fascinating properties, growth methods, and corresponding thermodynamic stabilities.
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Affiliation(s)
- Xiaoxu Zhao
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 13 Centre for Life Sciences, #05-01, 28 Medical Drive, Singapore, 117456, Singapore
| | - Shoucong Ning
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117575, Singapore
| | - Wei Fu
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
| | - Stephen J Pennycook
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 13 Centre for Life Sciences, #05-01, 28 Medical Drive, Singapore, 117456, Singapore
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117575, Singapore
| | - Kian Ping Loh
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 13 Centre for Life Sciences, #05-01, 28 Medical Drive, Singapore, 117456, Singapore
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10
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Yamashita S, Kikkawa J, Yanagisawa K, Nagai T, Ishizuka K, Kimoto K. Atomic number dependence of Z contrast in scanning transmission electron microscopy. Sci Rep 2018; 8:12325. [PMID: 30120323 PMCID: PMC6098135 DOI: 10.1038/s41598-018-30941-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 08/08/2018] [Indexed: 11/12/2022] Open
Abstract
Annular dark-field (ADF) imaging by scanning transmission electron microscopy (STEM) is a common technique for material characterization with high spatial resolution. It has been reported that ADF signal is proportional to the nth power of the atomic number Z, i.e., the Z contrast in textbooks and papers. Here we first demonstrate the deviation from the power-law model by quantitative experiments of a few 2D materials (graphene, MoS2 and WS2 monolayers). Then we elucidate ADF signal of single atoms using simulations to clarify the cause of the deviation. Two major causes of the deviation from the power-law model will be pointed out. The present study provides a practical guideline for the usage of the conventional power-law model for ADF imaging.
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Affiliation(s)
- Shunsuke Yamashita
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Jun Kikkawa
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Keiichi Yanagisawa
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Takuro Nagai
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Kazuo Ishizuka
- HREM Research Inc., 14-48 Matsukazedai, Higashimatsuyama, Saitama, 355-0055, Japan
| | - Koji Kimoto
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan.
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11
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Kimoto K, Ishizuka K. Rapid measurement of low-order aberrations using Fourier transforms of crystalline Ronchigrams. Ultramicroscopy 2017; 180:59-65. [PMID: 28343726 DOI: 10.1016/j.ultramic.2017.03.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 03/13/2017] [Accepted: 03/17/2017] [Indexed: 10/19/2022]
Abstract
The aberrations of the objective lens should be measured and adjusted to realize high spatial resolution in scanning transmission electron microscopy (STEM). Here we report a method of measuring low-order aberrations using the Fourier transforms of Ronchigrams of an arbitrary crystal such as a specimen of interest. We have applied this technique to measure first- and second-order geometrical aberrations using typical standard specimens. Focus and twofold astigmatism are measured using two Ronchigrams obtained under different foci. Axial coma and threefold astigmatism are evaluated using the Fourier transforms of small subareas of a Ronchigram. The time dependences of focus and twofold astigmatism are examined using this technique for an aberration-corrected microscope.
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Affiliation(s)
- Koji Kimoto
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
| | - Kazuo Ishizuka
- HREM Research Inc., 14-48 Matsukazedai, Higashimatsuyama, Saitama 355-0055, Japan
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12
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Oshima Y, Lee S, Takayanagi K. Visualization of lithium ions by annular bright field imaging. Microscopy (Oxf) 2016; 66:15-24. [DOI: 10.1093/jmicro/dfw098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 09/13/2016] [Indexed: 11/15/2022] Open
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13
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Koshiya S, Yamashita S, Kimoto K. Microscopic observation of dye molecules for solar cells on a titania surface. Sci Rep 2016; 6:24616. [PMID: 27087005 PMCID: PMC4834531 DOI: 10.1038/srep24616] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 03/21/2016] [Indexed: 01/16/2023] Open
Abstract
The lateral distribution and coverage of Ru-based dye molecules, which are used for dye-sensitized solar cells (DSCs), were directly examined on a titania surface using high-resolution scanning transmission electron microscopy (STEM). The clean surface of a free-standing titania nanosheet was first confirmed with atomic resolution, and then, the nanosheet was used as a substrate. A single dye molecule on the titania nanosheet was visualized for the first time. The quantitative STEM images revealed an inhomogeneous dye-molecule distribution at the early stage of its absorption, i.e., the aggregation of the dye molecules. The majority of the titania surface was not covered by dye molecules, suggesting that optimization of the dye molecule distribution could yield further improvement of the DSC conversion efficiencies.
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Affiliation(s)
- Shogo Koshiya
- Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Shunsuke Yamashita
- Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.,Department of Applied Chemistry, Kyushu University, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Koji Kimoto
- Surface Physics and Structure Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.,Department of Applied Chemistry, Kyushu University, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
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14
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Al Qahtani HS, Kimoto K, Bennett T, Alvino JF, Andersson GG, Metha GF, Golovko VB, Sasaki T, Nakayama T. Atomically resolved structure of ligand-protected Au9 clusters on TiO2 nanosheets using aberration-corrected STEM. J Chem Phys 2016; 144:114703. [PMID: 27004889 DOI: 10.1063/1.4943203] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Triphenylphosphine ligand-protected Au9 clusters deposited onto titania nanosheets show three different atomic configurations as observed by scanning transmission electron microscopy. The configurations observed are a 3-dimensional structure, corresponding to the previously proposed Au9 core of the clusters, and two pseudo-2-dimensional (pseudo-2D) structures, newly found by this work. With the help of density functional theory (DFT) calculations, the observed pseudo-2D structures are attributed to the low energy, de-ligated structures formed through interaction with the substrate. The combination of scanning transmission electron microscopy with DFT calculations thus allows identifying whether or not the deposited Au9 clusters have been de-ligated in the deposition process.
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Affiliation(s)
- Hassan S Al Qahtani
- Flinders Centre for NanoScale Science and Technology, Flinders University, Adelaide SA 5001, Australia
| | - Koji Kimoto
- National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
| | - Trystan Bennett
- Department of Chemistry, The University of Adelaide, Adelaide SA 5005, Australia
| | - Jason F Alvino
- Department of Chemistry, The University of Adelaide, Adelaide SA 5005, Australia
| | - Gunther G Andersson
- Flinders Centre for NanoScale Science and Technology, Flinders University, Adelaide SA 5001, Australia
| | - Gregory F Metha
- Department of Chemistry, The University of Adelaide, Adelaide SA 5005, Australia
| | - Vladimir B Golovko
- Department of Chemistry, The MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Canterbury, Christchurch 8140, New Zealand
| | - Takayoshi Sasaki
- WPI-MANA, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Tomonobu Nakayama
- WPI-MANA, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
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