Isotopic effects on the phonon modes in boron carbide

Werheit, H.; Kuhlmann, U.; Rotter, H.; Shalamberidze, Sulkhan

doi:10.1088/0953-8984/22/39/395401

Cited by 26 publications

(49 citation statements)

References 32 publications

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“…Experimentally 27 , the peak at ~1600 cm -1 has been attributed to a chain stretch term, 1100 cm -1 is attributed to the inter-icosahedral B-B vibrations, and the peaks at 800-900 cm -1 to intra-icosahedral B-B vibrations, corresponding to the assignments in this investigation. We note that previous authors 28 maintain that the Raman band at around 1600 cm -1 arises solely from the presence of carbonaceous impurities.…”

Section: Bonding Within and Between Cages (Intra-and Inter-icosahedrasupporting

confidence: 62%

Impact scenarios in boron carbide: A computational study

Sugden

Plant

Bell

2016

J. Theor. Comput. Chem.

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The effect of radiative impacts on the structure of boron carbide has been studied by both classical and ab initio simulations. As a part of this study, a new forcefield was developed for use in studying boron carbide materials. Impact scenarios in boron carbide were simulated in order to investigate the exceptional resistance of this material, and other icosahedral boron solids, to high-energy impact events.It was observed that interstitial defects created by radiative impacts are likely to be quenched locally, utilising the high substitutional disorder of chains and cages in the boron carbide structure, rather than via impacted atoms recombining with their vacated lattice site.

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Section: Bonding Within and Between Cages (Intra-and Inter-icosahedrasupporting

confidence: 62%

Impact scenarios in boron carbide: A computational study

Sugden

Plant

Bell

2016

J. Theor. Comput. Chem.

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“…Emin and coworkers proposed a small bipolaron hopping mechanism [1,40,[45][46][47][48][49]. This model is still under debate [3,[50][51][52].…”

Section: Energy Gapmentioning

confidence: 99%

Theoretical study of the structure of boron carbideB13C2

2014

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We have resolved long-standing discrepancies between the theoretical and experimental crystal structures of boron carbide B 13 C 2 . Theoretical studies predict that B 13 C 2 should be stoichiometric and have the highest symmetry of the boron carbides. Experimentally, B 13 C 2 is a semiconductor and many defect states have been reported, particularly in the CBC chain. Reconciling the disordered states of the chain, the chemical composition, and the lowest-energy state is problematic. We have solved this problem by constructing a structural model where approximately three-quarters of the unit cells contain (B 11 C)(CBC) and one-quarter of them contain (B 12 ) (B 4 ). This structural model explains many experimental results, such as the large thermal factors in x-ray diffraction and the broadening of the Raman spectra, without introducing unstable CBB chains. The model also solves the energy-gap problem. We show that there are many arrangements of these two types of unit cells, which are energetically almost degenerate. This demonstrates that boron carbides are well described by a geometrically frustrated system, similar to that proposed for β-rhombohedral boron.

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“…For B 4 C, 840, 1086, 1420, and 1552 cm −1 are the dominant peaks present in the FT‐IR spectra. The peak at 840 cm −1 is attributed to intraicosahedral B─B vibrations, 1086 cm −1 is ascribed to the inter‐icosahedral B─B vibrations, 1420 cm −1 correspond to the B─O stretching vibration, and the absorption band at approximately 1552 cm −1 is considerably impacted by both carbon and boron isotopes . As seen in Figure B, apart from the characteristic absorption peaks of B 4 C, peaks appear at approximately 2952 and 2880 cm −1 , corresponding to the methylene stretching vibration, and the methylene twisted vibration absorption peaks correspond to the peak at approximately 1458 cm −1 .…”

Section: Resultsmentioning

confidence: 94%

Functionalized boron carbide for enhancement of anticorrosion performance of epoxy resin

Wang

Xie

et al. 2017

Polymers for Advanced Techs

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In this study, epoxy coatings were modified by adding various compositions of B 4 C particles. In order to achieve proper dispersion of particles in the epoxy coating and increasing chemical interactions between particles and polymeric coating, the surface of the B 4 C particles was treated with γ-(2,3-epoxypropoxy) propytrimethoxysilane (KH560). The surface modification and microstructure of B 4 C were characterized by Fourier transform infrared, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. Electrochemical impedance spectroscopy was also used to evaluate the impedance of coatings. The results revealed that the KH560 not only enhanced the interaction between B 4 C particles and epoxy resin but also exhibited a remarkable ability to improve the anticorrosion performance of epoxy resin. The epoxy coating with the 3 wt% B 4 C-KH560 particles exhibited the best anticorrosion performance, which can be attributed to the best uniform dispersion of the B 4 C-KH560 particles, and the particles effectively block the aggressive species (Cl − , O 2 , and H 2 O) from the coating.

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Isotopic effects on the phonon modes in boron carbide

Cited by 26 publications

References 32 publications

Impact scenarios in boron carbide: A computational study

Impact scenarios in boron carbide: A computational study

Theoretical study of the structure of boron carbideB13C2

Functionalized boron carbide for enhancement of anticorrosion performance of epoxy resin

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