Unraveling the Atomic Structure of Ultrafine Iron Clusters

Wang, Hongtao; Li, Kun; Yao, Yingbang; Wang, Qingxiao; Cheng, Yingchun; Schwingenschlögl, Udo; Zhang, Xi Xiang; Yang, Wei

doi:10.1038/srep00995

Cited by 25 publications

(39 citation statements)

References 36 publications

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“…The rhombus shaped lattice (Fig. 2c) is comparable with the rhombus lattice of AB Bernal graphite prevailing in the literature20212223242526, where each white dot of the AB rhombus shaped lattice is due to amplification from the two overlapped atoms of the AB bilayer graphene (Fig. 3b).…”

Section: Resultssupporting

confidence: 65%

The Nature of Metastable AA’ Graphite: Low Dimensional Nano- and Single-Crystalline Forms

Lee

Kim

Hembram

et al. 2016

Sci Rep

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Over the history of carbon, it is generally acknowledged that Bernal AB stacking of the sp2 carbon layers is the unique crystalline form of graphite. The universal graphite structure is synthesized at 2,600~3,000 °C and exhibits a micro-polycrystalline feature. In this paper, we provide evidence for a metastable form of graphite with an AA’ structure. The non-Bernal AA’ allotrope of graphite is synthesized by the thermal- and plasma-treatment of graphene nanopowders at ~1,500 °C. The formation of AA’ bilayer graphene nuclei facilitates the preferred texture growth and results in single-crystal AA’ graphite in the form of nanoribbons (1D) or microplates (2D) of a few nm in thickness. Kinetically controlled AA’ graphite exhibits unique nano- and single-crystalline feature and shows quasi-linear behavior near the K-point of the electronic band structure resulting in anomalous optical and acoustic phonon behavior.

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Section: Resultssupporting

confidence: 65%

The Nature of Metastable AA’ Graphite: Low Dimensional Nano- and Single-Crystalline Forms

Lee

Kim

Hembram

et al. 2016

Sci Rep

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“…However, the liquification may not occur homogeneously under the experimental conditions. In fact, experimental evidences show that the catalyst particles in graphene channels normally comprise a crystalline structure, or exist in solid state at least . Therefore, an insightful understanding on the graphene cutting energetics and kinetics needs to be further explored.…”

Section: Tm‐catalyzed Cuttingmentioning

confidence: 99%

Making graphene nanoribbons: a theoretical exploration

Chen

Wang

2016

WIREs Comput Mol Sci

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Graphene nanoribbons (GNRs), thin and long strips of single carbon layer, exhibit very charming electronic and magnetic properties, and show great promising applications in electronics and optoelectronics devices. Therefore, reliable and efficient techniques of making high-quality GNRs have attracted enormous interests in recent years. Numerous methods of making GNRs, including both top-down and bottom-up schemes, have been developed, and among them, metal-catalyzed and oxidative cutting of graphene and/or carbon nanotube as two most promising approaches have been widely used to fabricate GNRs with different widths, edges, and defects. However, precise control of mass production of narrow GNRs with well-defined and smooth edges is still very challenging. To reach this goal, it is essential to well understand the underlying mechanisms of making GNRs in different conditions, such as the force that drives the cutting process, catalyst, and agent-dependent cutting behavior, orientation-selective cutting at the atomic level. Recently, theoretical investigations based on quantum chemical calculations have made great progress in this area.

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“…Thus, the high Emax and low Ed values of the light elements, especially hydrogen, would result in hydride decomposition even at relatively low operating voltages in the TEM. Low TEM operating voltages, e.g., 60 keV for graphene [12], are conventionally effective for reducing knock-on damage, but the Emax of hydrogen and lithium cannot be reduced below their Ed values in an usual TEM. Lowering the operating voltage to avoid ballistic damage to hydrides is therefore ineffective and would encounter problems with electron elastic scattering cross-section, which governs the probability of the elastic scattering event and also impacts ballistic damage.…”

Section: Elastic Scattering Damagementioning

confidence: 99%

“…Although the use of low operating voltage is usually effective for observing materials composed of light elements, e.g., below 100 keV for carbon materials such as nanotubes [10][11] and graphene [12], this method may be unsuitable for observing light metal hydrides due to the excessively low threshold energy of displacement for hydrogen (and lithium), as well as the excessive energy transfer from incident electrons to hydrogen (and lithium) nuclei. In this study, the effects of constituting element and incident-electron energy on the irradiation damage to lithium, sodium, and magnesium hydrides (LiH, NaH, and MgH2) in the TEM were theoretically and experimentally investigated.…”

mentioning

confidence: 99%

Interaction of electrons with light metal hydrides in the transmission electron microscope

et al. 2014

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Transmission electron microscope (TEM) observation of light metal hydrides is complicated by the instability of these materials under electron irradiation. In this study, the electron kinetic energy dependences of the interactions of incident electrons with lithium, sodium, and magnesium hydrides, as well as the constituting element effect on the interactions, were theoretically discussed, and electron irradiation damage to these hydrides was examined using in-situ TEM. The results indicate that high incident electron kinetic energy helps alleviate the irradiation damage resulting from inelastic or elastic scattering of the incident electrons in the TEM. Therefore, observations and characterizations of these materials would benefit from increased, instead decreased, TEM operating voltage. signals resulting from these phenomena allow for powerful microscopy and spectrometry applications in the TEM, e.g., imaging, diffraction, energy dispersive X-ray spectroscopy (EDS), and electron energy-loss spectrometry (EELS). However, these advantages are associated with detrimental beam damage, which limits the application of the TEM in materials that are sensitive to high-energy electron radiation.Unfortunately, most advanced hydrogen storage materials consisting of light elements are partially subject to this limitation. To achieve a high hydrogen capacity [1][2], the majority of currently studied hydrogen storage materials are composed of compounds and complexes containing light elements [3] such as lithium, sodium, and magnesium. These materials are

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Unraveling the Atomic Structure of Ultrafine Iron Clusters

Cited by 25 publications

References 36 publications

The Nature of Metastable AA’ Graphite: Low Dimensional Nano- and Single-Crystalline Forms

The Nature of Metastable AA’ Graphite: Low Dimensional Nano- and Single-Crystalline Forms

Making graphene nanoribbons: a theoretical exploration

Interaction of electrons with light metal hydrides in the transmission electron microscope

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