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Tian M, Tennyson WD, Yoon M, Puretzky AA, Geohegan DB, Duscher G, Eres G. Role of Curvature in Stabilizing Boron-Doped Nanocorrugated Graphene. ACS APPLIED MATERIALS & INTERFACES 2024; 16:1276-1282. [PMID: 38109559 DOI: 10.1021/acsami.3c10664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
Boron-doped carbon nanostructures have attracted great interest recently because of their remarkable electrocatalytic performance comparable to or better than that of conventional metal catalysts. In a previous work (Carbon 123, 605 (2017)), we reported that along with significant performance improvement, B doping enhances the oxidation resistance of few-layer graphene (FLG) that provides increased structural stability for intermediate-temperature fuel-cell electrodes. In general, detailed characterization of the atomic and electronic structure transformations that occur in B-doped carbon nanostructures during fuel-cell operation is lacking. In this work, we use aberration-corrected scanning transmission electron microscopy, nanobeam electron diffraction, and electron energy-loss spectroscopy (EELS) to characterize the atomic and electronic structures of B-doped FLG before and after fuel-cell operation. These data point to the nanoscale corrugation of B-doped FLGs as the key factor responsible for increased stability and high corrosion resistance. The similarity of the 1s to π* and σ* transition features in the B K-edge EELS to those in B-doped carbon nanotubes provides an estimate for the curvature of nanocorrugation in B-FLG.
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Affiliation(s)
- Mengkun Tian
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Wesley D Tennyson
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Mina Yoon
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Alexander A Puretzky
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - David B Geohegan
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Gerd Duscher
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Gyula Eres
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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2
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Shyam Kumar CN, Chakravadhanula VSK, Riaz A, Dehm S, Wang D, Mu X, Flavel B, Krupke R, Kübel C. Understanding the graphitization and growth of free-standing nanocrystalline graphene using in situ transmission electron microscopy. NANOSCALE 2017; 9:12835-12842. [PMID: 28799608 DOI: 10.1039/c7nr03276e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Graphitization of polymers is an effective way to synthesize nanocrystalline graphene on different substrates with tunable shape, thickness and properties. The catalyst free synthesis results in crystallite sizes on the order of a few nanometers, significantly smaller than commonly prepared polycrystalline graphene. Even though this method provides the flexibility of graphitizing polymer films on different substrates, substrate free graphitization of freestanding polymer layers has not been studied yet. We report for the first time the thermally induced graphitization and domain growth of free-standing nanocrystalline graphene thin films using in situ TEM techniques. High resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and electron energy loss spectroscopy (EELS) techniques were used to analyze the graphitization and the evolution of nanocrystalline domains at different temperatures by characterizing the crystallinity and domain size, further supported by ex situ Raman spectroscopy. The graphitization was comparable to the substrate supported heating and the temperature dependence of graphitization was analyzed. In addition, the in situ analysis of the graphitization enabled direct imaging of some of the growth processes taking place at different temperatures.
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Affiliation(s)
- C N Shyam Kumar
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany.
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González-García P, Arenas-Esteban D, Ávila-Brande D, Urones-Garrote E, Otero-Díaz LC. Nickelocene as precursor of microporous organometallic-derived carbon and nickel oxide-carbon nanocomposite. J Colloid Interface Sci 2017; 490:410-419. [PMID: 27914340 DOI: 10.1016/j.jcis.2016.11.034] [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: 10/04/2016] [Accepted: 11/09/2016] [Indexed: 11/18/2022]
Abstract
Microporous flower-like and spherical carbon particles, made of graphene-like layers, have been obtained via chlorination of nickelocene (Ni(C5H5)2). Their mechanism of formation, in terms of morphology and micro-nanostructure, has been followed from 200 to 900°C. Conventional transmission electron microscopy and high-resolution-TEM observations allow determining that their structure is made of highly disordered graphene-like layers. The Raman spectrum of the high temperature sample exhibits the characteristics D and G bands. The peak positions, the ratio of their intensities (ID/IG) and full width at half maximum suggest a high degree of disorder in the nanostructures. The calculated in-plane correlation length of these graphene-like layers is 1.15nm. In all the carbon particles, electron energy-loss spectroscopy shows sp2 carbon bonding content higher than 95% and mass density in the range of 1.0-1.6g/cm3. Textural studies show Type I adsorption isotherms with surface area of 922m2/g for the sample produced at 900°C. In addition, the basic hydrothermal treatment of the sample chlorinated at 600°C yields a composite material with NiO nanoparticles well dispersed within the carbon matrix.
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Affiliation(s)
- P González-García
- CONACYT - Centro de Ingeniería y Desarrollo Industrial, 76125 Querétaro, Querétaro, Mexico.
| | - D Arenas-Esteban
- Departamento de Química Inorgánica, Facultad de Ciencias Químicas, Universidad Complutense, E-28040 Madrid, Spain
| | - D Ávila-Brande
- Departamento de Química Inorgánica, Facultad de Ciencias Químicas, Universidad Complutense, E-28040 Madrid, Spain.
| | - E Urones-Garrote
- Centro Nacional de Microscopía Electrónica, Universidad Complutense, E-28040 Madrid, Spain
| | - L C Otero-Díaz
- Departamento de Química Inorgánica, Facultad de Ciencias Químicas, Universidad Complutense, E-28040 Madrid, Spain
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Wei BQ, Yan N, Gao JX, Li DD, Shang ZG, He K. Absolute thickness measurement of pyrolytic graphite spheroids by STEM-EELS. Micron 2016; 91:41-48. [PMID: 27721207 DOI: 10.1016/j.micron.2016.10.001] [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: 07/18/2016] [Revised: 10/02/2016] [Accepted: 10/02/2016] [Indexed: 10/20/2022]
Abstract
This paper studies the absolute thickness measurement of pyrolytic graphite spheroids (GSs) by using STEM-EELS mode with log-ratio method and Kramers-Kroning (K-K) method, taking the measured thickness from TEM image as reference that is the diameter of GSs ranging from 60 to 250nm. The effect of collection semi-angle (β) on thickness measurement has been investigated. It is found that in general the thickness obtained by K-K analysis with surface effect corrected shows the best accuracy, followed by K-K sum rule and then log-ratio method for the three different collection semi-angles of 12.4, 17.3 and 21.1mrad applied. Of these angles, the smallest one gives an overestimated result and the largest one gives an underestimated result, whereas between the two, the angle of 17.3mrad that is about 2x convergence semi-angle (9.0mrad) is identified as more appropriate for K-K analysis. The surface-scattering correction, inelastic mean free path of GS and effect of refractive index n on thickness measurement for different β angles are also investigated. Moreover, the optical property deduced from the data collected at the center of graphite spheroid, which is related to its microstructure, is characterized by K-K analysis.
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Affiliation(s)
- B Q Wei
- School of Materials Science and Engineering, Central South University, Changsha 410083, China
| | - N Yan
- Advanced Research Centre, Central South University, Changsha 410083, China
| | - J X Gao
- School of Materials Science and Engineering, Central South University, Changsha 410083, China
| | - D D Li
- School of Materials Science and Engineering, Central South University, Changsha 410083, China
| | - Z G Shang
- Advanced Research Centre, Central South University, Changsha 410083, China
| | - K He
- School of Materials Science and Engineering, Central South University, Changsha 410083, China; Advanced Research Centre, Central South University, Changsha 410083, China.
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Diociaiuti M, Casciardi S, Sisto R. The sp 2 and sp 3 fractions of unknown carbon materials: electron energy-loss near-edge structure analysis of C-K spectra acquired under the magic-angle condition by the electron nanobeam technique. Micron 2016; 90:97-107. [PMID: 27639109 DOI: 10.1016/j.micron.2016.07.005] [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: 05/20/2016] [Revised: 07/14/2016] [Accepted: 07/14/2016] [Indexed: 10/21/2022]
Abstract
A method is described for the quantification of the sp2, sp3 and intermediate hybridizations in several carbon (C) material samples. Electron energy-loss near-edge spectra were acquired using fast electrons (120keV) in an electron microscope in nanobeam configuration under the so-called "magic-angle" condition, and were analysed to extract the sp2 and sp3 fractions, and identify the possible mixed sp2+ε hybridizations. The method consists in projecting the unknown spectra on a basis made up of pure sp2 and sp3 spectra, obtained under the same experimental conditions from graphite and diamond crystals, respectively. The residual spectra contain information about the intermediate hybridizations sp2+ε occurring in the samples. The method was successfully tested on "ab initio" numerically generated spectra relative to amorphous C materials. Finally, it was applied to actual C amorphous and pyrolytic samples, and results were compared to those obtained by the most commonly used, conventional "three-Gaussian" method. The combined application of electron diffraction and spectroscopy, in the nanobeam configuration, yielded useful information about the atomic and electronic structure from very small volumes of the unknown C material.
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Affiliation(s)
- Marco Diociaiuti
- Italian National Institute of Health (ISS), Department of Technology and Health, Viale Regina Elena 299, 00161 Rome, Italy.
| | - Stefano Casciardi
- National Institute for Insurance against Accidents at Work (INAIL Research), Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Via Fontana Candida 1, 00040 Monte Porzio Catone, Rome, Italy
| | - Renata Sisto
- National Institute for Insurance against Accidents at Work (INAIL Research), Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Via Fontana Candida 1, 00040 Monte Porzio Catone, Rome, Italy
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McDougall NL, Nicholls RJ, Partridge JG, McCulloch DG. The near edge structure of hexagonal boron nitride. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2014; 20:1053-1059. [PMID: 24758771 DOI: 10.1017/s1431927614000737] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Hexagonal boron nitride (hBN) is a promising material for a range of applications including deep-ultraviolet light emission. Despite extensive experimental studies, some fundamental aspects of hBN remain unknown, such as the type of stacking faults likely to be present and their influence on electronic properties. In this paper, different stacking configurations of hBN are investigated using CASTEP, a pseudopotential density functional theory code. AB-b stacking faults, in which B atoms are positioned directly on top of one another while N atoms are located above the center of BN hexagons, are shown to be likely in conventional AB stacked hBN. Bandstructure calculations predict a single direct bandgap structure that may be responsible for the discrepancies in bandgap type observed experimentally. Calculations of the near edge structure showed that different stackings of hBN are distinguishable using measurements of core-loss edges in X-ray absorption and electron energy loss spectroscopy. AB stacking was found to best reproduce features in the experimental B and N K-edges. The calculations also show that splitting of the 1s to π* peak in the B K-edge, recently observed experimentally, may be accounted for by the presence of AB-b stacking faults.
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Affiliation(s)
- Nicholas L McDougall
- 1Department of Physics,School of Applied Sciences,RMIT University,GPO Box 2476 V,Melbourne,Victoria 3001,Australia
| | - Rebecca J Nicholls
- 2Department of Materials,University of Oxford,Parks Rd,Oxford,Oxfordshire,OX1 3PH,UK
| | - Jim G Partridge
- 1Department of Physics,School of Applied Sciences,RMIT University,GPO Box 2476 V,Melbourne,Victoria 3001,Australia
| | - Dougal G McCulloch
- 1Department of Physics,School of Applied Sciences,RMIT University,GPO Box 2476 V,Melbourne,Victoria 3001,Australia
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Hesketh J, Ward M, Dowson D, Neville A. The composition of tribofilms produced on metal-on-metal hip bearings. Biomaterials 2014; 35:2113-9. [DOI: 10.1016/j.biomaterials.2013.11.065] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 11/21/2013] [Indexed: 12/12/2022]
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9
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10
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ASLAM Z, ABRAHAM M, BROWN A, RAND B, BRYDSON R. Electronic property investigations of single-walled carbon nanotube bundlesin situwithin a transmission electron microscope: an evaluation. J Microsc 2008; 231:144-55. [DOI: 10.1111/j.1365-2818.2008.02025.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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11
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Ma C, Xiao RJ, Geng HX, Yang HX, Tian HF, Che GC, Li JQ. Investigation of hole states near the Fermi level in Nb(1-)(x)Mg(x)B(2) by electron energy-loss spectroscopy and first-principles calculations. Ultramicroscopy 2007; 108:320-6. [PMID: 17560031 DOI: 10.1016/j.ultramic.2007.05.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Revised: 04/04/2007] [Accepted: 05/01/2007] [Indexed: 10/23/2022]
Abstract
The fine structures of the electron energy-loss spectra (EELS) for the B-K edge have been examined in NbB(2) and superconducting Nb(0.75)Mg(0.25)B(2). The experimental results are analyzed based on the calculations of density functional theory (DFT) using the Wien2k code. The results of the EELS spectra and the angular decomposition of the density of states (DOS) reveal that both the B p(z) and B p(x)+p(y) states in NbB(2) have large weights at the Fermi energy due to intersheet covalent bonding with notable hybridization between the Nb 4d and B 2p states. This kind of hybridization also results in different core-hole behaviors for the B-K edge in two orthogonal crystallographic orientations. The best fit between experimental and theoretical data is achieved with consideration of the core-hole effect of the B 1s states, in particular for the q perpendicular c spectra. Analysis of the electronic structure of the Nb(1-)(x)Mg(x)B(2) superconductors suggests that confinement of the intersheet covalent bonding is likely to be favorable for the improvement of superconductivity in this kind of materials.
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Affiliation(s)
- C Ma
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
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12
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Bocquet F, Bernier N, Saikaly W, Brosset C, Thibault J, Charaï A. Evolution of ELNES spectra as a function of experimental settings for any uniaxial specimen: A fully relativistic study. Ultramicroscopy 2007; 107:81-94. [PMID: 16870339 DOI: 10.1016/j.ultramic.2006.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2005] [Revised: 05/19/2006] [Accepted: 05/30/2006] [Indexed: 10/24/2022]
Abstract
We perform calculations of the fully relativistic, corrected geometrical weighting of the pi* and sigma* transitions measured from the 1s core loss electron energy loss spectroscopy (EELS) spectrum in any uniaxial specimen. We present a complete calculation of the differential scattering cross-section (DSCS), taking into account the collection angle, the illumination angle and the tilt of the sample over the optical axis. Owing to high electron velocity in an EELS experiment, the relativistic correction has to be considered. We thus, present a relativistic, corrected DSCS by using the theory recently developed by Jouffrey et al. [Ultramicroscopy 102 (2004) 61] and P. Schattschneider et al. [Phys. Rev. B 72 (2005) 045142]. The relativistic correction is first performed in the natural coordinate system of the scattering event. We then point out a straightforward method to introduce this correction in the microscopic coordinate system, where all calculations have to be done to be experimentally useful. Using the fully corrected DSCS, we present an expression predicting the evolution of the R=pi*/(pi*+sigma*) ratio (related to the ratio of sp2 and sp3 bondings) as a function of experimental settings. We show how the R-evolution can be predicted, for any experimental setting, by the knowledge of one unique reference value. We verify on graphite specimens, the validity of the R-calculation by comparing theoretical predictions presented in this work with experimental data published elsewhere [Daniels et al., Ultramicroscopy 96 (2003) 523 and Menon et al., Ultramicroscopy 74 (1998) 83].
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Affiliation(s)
- F Bocquet
- Laboratoire TECSEN, UMR 6122, Faculté des Sciences, Université Paul Cézanne-Aix Marseille III, 13397 Marseille Cedex 20, France.
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Hébert C, Schattschneider P, Franco H, Jouffrey B. ELNES at magic angle conditions. Ultramicroscopy 2006; 106:1139-43. [PMID: 16934931 DOI: 10.1016/j.ultramic.2006.04.030] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2005] [Revised: 01/12/2006] [Accepted: 04/05/2006] [Indexed: 11/17/2022]
Abstract
If one needs to cancel the effects of the anisotropy of the sample in a EELS experiment in the TEM, a particular couple of values for the collection and convergence angle must be used, called magic angle conditions (MAC). Recent developments in the theory have shown that a full relativistic treatment is mandatory to correctly describe this effect and that the MAC are strongly dependent on the acceleration voltage. We show how the analytical formula can be derived and give the exact analytical solution for the MAC which can then be easily applied to every practical case. We show the consequences of the energy dependence of the magic angle and that the parallelity of the beam will be the limiting factor for high acceleration voltages while for low acceleration voltages the contribution coming from Bragg spots may make it impossible to reach MAC.
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Affiliation(s)
- C Hébert
- Institut für Festkörperphysik, Technische Universität Wien, A-1040 Wien, Austria.
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14
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Le Bossé JC, Epicier T, Jouffrey B. Polarization dependence in ELNES: Influence of probe convergence, collector aperture and electron beam incidence angle. Ultramicroscopy 2006; 106:449-60. [PMID: 16442734 DOI: 10.1016/j.ultramic.2005.12.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2005] [Revised: 12/07/2005] [Accepted: 12/15/2005] [Indexed: 11/18/2022]
Abstract
The differential scattering cross section in electron energy loss near edge spectroscopy (ELNES) generally depends on the orientation of the Q wave vector transferred from the incident electron to an atomic core electron. In the case where the excited atom belongs to a threefold, fourfold or sixfold main rotation axis, the dipole cross section depends on the angle of Q with respect to this axis. In this paper, we restrict to this situation called dichroism. Furthermore, if we take into account the relativistic effects due to the high incident electron velocity, this dipole cross section also depends on the angle of Q with respect to the electron beam axis. It is due to these dependences that the shape of measured electron energy loss spectra varies with the electron beam incidence, the collector aperture, the incident beam convergence and the incident electron energy. The existence of a particular beam incidence angle for which the scattering cross section becomes independent of collection and beam convergence semi-angles is clearly underscored. Conversely, it is shown that EELS spectra do not depend on the beam incidence angle for a set of particular values of collection and convergence semi-angles. Particularly, in the case of a parallel incident beam, there is a collection semi-angle (often called magic angle) for which the cross section becomes independent of the beam orientation. This magic angle depends on the incident beam kinetic energy. If the incident electron velocity V is small compared with the light velocity c, this magic angle is about 3.975theta(E) (theta(E) is the scattering angle). It decreases to 0 when V approaches c. These results are illustrated in the case of the K boron edge in the boron nitride.
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Affiliation(s)
- J C Le Bossé
- Groupe d'Etudes de Métallurgie Physique et de Physique des Matériaux, Institut National des Sciences Appliquées, Bât. Blaise Pascal, 7 avenue Jean Capelle, F-69621 Villeurbanne Cedex, France.
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Koshino M, Masunaga YH, Nemoto T, Kurata H, Isoda S. Radiation damage analysis of 7,7,8,8,-tetracyanoquinodimethane (TCNQ) and 2,3,5,6,-tetrafluoro-7,7,8,8,-tetracyanoquinodimethane (F4TCNQ) by electron diffraction and electron energy loss spectroscopy. Micron 2005; 36:271-9. [PMID: 15725597 DOI: 10.1016/j.micron.2004.12.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2004] [Revised: 12/27/2004] [Accepted: 12/27/2004] [Indexed: 10/25/2022]
Abstract
The electron irradiation sensitivity is compared between TCNQ and F(4)TCNQ. The characteristic doses, D(1/e), determined by the attenuation of the diffraction intensities are 0.08-0.11Ccm(-2) for TCNQ, and 0.04-0.06Ccm(-2) for F(4)TCNQ, respectively. It is found that F(4)TCNQ is more sensitive to radiation damage than TCNQ in spite of the substitution of hydrogen with fluorine. From electron energy-loss spectroscopy (EELS), it is found that the damaging process for the two materials begins in a similar way, as seen from mass loss and spectrum changes observed for doses which exceed the characteristic dose. Although sensitive to the sample orientation, the carbon K-edge fine structures of TCNQ are almost preserved below the critical dose. Theoretical calculation predicts that the scission of hydrogen contributes to the spectrum shape very little compared to nitrogen scission. Beyond the characteristic dose, fluorine loss from F(4)TCNQ occurs faster than nitrogen loss but little loss of carbon is observed. In a similar way, nitrogen loss from TCNQ occurs beyond the characteristic dose, while carbon appears constant. From detailed analysis of the carbon and nitrogen K-edge fine structures of TCNQ and F(4)TCNQ, it is found that the pi* peak of nitrogen in TCNQ decreases below the characteristic dose, while pi* loss of nitrogen in F(4)TCNQ, and pi* loss and sigma* increase of carbon in both materials are observed beyond the characteristic dose. The changes in the fine structures are believed to be due to the chemical alteration such as cross-linking, in which the pi-bonding system of nitrogen or carbon turns into sigma-bonding. The difference in characteristic dose between TCNQ and F(4)TCNQ is explained by considering "effective molecular occupancy", where F(4)TCNQ has a larger intermolecular empty space than TCNQ.
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Affiliation(s)
- Masanori Koshino
- Advanced Research Center for Beam Science, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
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16
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Jouffrey B, Schattschneider P, Hébert C. The magic angle: a solved mystery. Ultramicroscopy 2004; 102:61-6. [PMID: 15556701 DOI: 10.1016/j.ultramic.2004.08.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2004] [Revised: 08/11/2004] [Accepted: 08/11/2004] [Indexed: 10/26/2022]
Abstract
We resolve the long-standing mysterious discrepancy between the experimental magic angle in EELS--approximately 2theta(E)--and the quantum mechanical prediction of approximately 4theta(E). A relativistic approach surpassing the usually applied kinematic correction yields a magic angle close to the experimental value. The reason is that the relativistic correction of the inelastic scattering cross section in anisotropic systems is significantly higher than in isotropic ones.
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Affiliation(s)
- B Jouffrey
- LMSS-Mat, CNRS-URA 850, Ecole Centrale Paris, Gde Voie des Vignes, F-92295 Châtenay-Malabry, France
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Hébert C, Jouffrey B, Schattschneider P. Comment on “Experimental and theoretical evidence for the magic angle in transmission electron energy loss spectroscopy” by H. Daniels, A. Brown, A. Scott, T. Nichells, B. Rand and R. Brydson. Ultramicroscopy 2004; 101:271-3. [PMID: 15450673 DOI: 10.1016/j.ultramic.2004.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2003] [Revised: 06/14/2004] [Accepted: 07/05/2004] [Indexed: 11/22/2022]
Affiliation(s)
- C Hébert
- Institut für Festkörperphysik, Technische Universität Wien, Wiedner Haupstrasse 8-10, A-1040 Wien, Austria.
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18
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Recent Developments in the Microscopy of Ceramics. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/s1076-5670(04)32004-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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