Novel XAFS capabilities at ELETTRA synchrotron light source

Cicco, Andrea Di; Aquilanti, Giuliana; Minicucci, Marco; Principi, Emiliano; Novello, Nicola; Cognigni, Andrea; Olivi, Luca

doi:10.1088/1742-6596/190/1/012043

Cited by 217 publications

(162 citation statements)

References 18 publications

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“…Good quality W L 3 -edge X-ray absorption spectrum of tungsten metallic foil (99.95%, Goodfellow) was recorded at T = 300 K in transmission mode at the ELETTRA XAFS bending magnet beamline [55]. The storage ring operated in the top-up multibunch mode at the energy E = 2.4 GeV and current I = 160 mA.…”

Section: Methodsmentioning

confidence: 99%

Advanced approach to the local structure reconstruction and theory validation on the example of the W L₃-edge extended x-ray absorption fine structure of tungsten

Jonane

Anspoks

Kuzmin

2018

Modelling Simul. Mater. Sci. Eng.

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Abstract. Atomistic simulations of the experimental W L 3 -edge extended X-ray absorption fine structure (EXAFS) of bcc tungsten at T = 300 K were performed using classical molecular dynamics (MD) and reverse Monte Carlo (RMC) methods. The MD-EXAFS method based on the results of MD simulations allowed us to access the structural information, encoded in EXAFS, beyond the first coordination shell and to validate the accuracy of two interaction potential models -the embedded atom model potential and the second nearest-neighbor modified embedded atom method potential. The RMC-EXAFS method was used for more elaborate analysis of the EXAFS data giving access to thermal disorder effects. The results of both methods suggest that the correlation in atomic motion in bcc tungsten becomes negligible above 8Å. This fact allowed us to use the EXAFS data to determine not only mean-square relative displacements of atomic W-W pair motion but also mean-square displacements of individual tungsten atoms, which are usually accessible from diffraction data only.

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Section: Methodsmentioning

confidence: 99%

Advanced approach to the local structure reconstruction and theory validation on the example of the W L₃-edge extended x-ray absorption fine structure of tungsten

Jonane

Anspoks

Kuzmin

2018

Modelling Simul. Mater. Sci. Eng.

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“…19 The electron energy and the average current were 2 GeV and 300 mA, respectively. The X-ray beam was monochromatized by two silicon crystals with flat (111) parallel reflecting faces; the harmonics influence was reduced by reflection from a Pt-coated mirror.…”

Section: Methodsmentioning

confidence: 99%

Local vibrational properties of GaAs studied by extended X-ray absorption fine structure

Ahmed

Aquilanti

Novello

et al. 2013

The Journal of Chemical Physics

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Extended X-ray absorption fine structure (EXAFS) has been measured at both the K edges of gallium and arsenic in GaAs, from 14 to 300 K, to investigate the local vibrational and thermodynamic behaviour in terms of bond expansion, parallel, and perpendicular mean square relative displacements and third cumulant. The separate analysis of the two edges allows a self-consistent check of the results and suggests that a residual influence of Ga EXAFS at the As edge cannot be excluded. The relation between bond expansion, lattice expansion, and expansion due to anharmonicity of the effective potential is quantitatively clarified. The comparison with previous EXAFS results on other crystals with the diamond or zincblende structure shows that the values of a number of parameters determined from EXAFS are clearly correlated with the fractional ionicity and with the strength and temperature interval of the lattice negative expansion. © 2013 AIP Publishing LLC.

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“…8 For these measurements, samples were prepared as pellets of the pure materials slightly diluted in BN (boron nitride). The absorption spectra were analyzed according to standard procedures 9 using the ATHENA program pack.…”

Section: Methodsmentioning

confidence: 99%

Raman and x-ray absorption spectroscopy study of the phase evolution induced by mechanical milling and thermal treatments inR2Ti2O
Sanjuán
¹
,
Guglieri
²
,
Díaz‐Moreno
³

et al. 2011
Phys. Rev. B
74
1
45
0
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We report here a study of the local order in R 2 Ti 2 O 7 , (R = Y, Gd, and Dy) pyrochlores obtained by mechanical milling (MM) performed by combining both Raman and x-ray absorption (XAS) spectroscopies. In addition to both as-milled and annealed MM samples, measurements have been also recorded by performing an in situ thermal treatment of the MM pyrochlores in the range from ambient to 1300• C. The analysis of both Raman and XAS data yields a disentangled view of the evolution of the different degree of structural disorder at the Ti and rare-earth sites of the MM samples with the thermal treatment. Moreover, this study allowed us to follow the structural transformation of the MM samples through the region where exothermic processes have been previously observed. Our experiments show that an average fluorite-like structure is never formed in these pyrochlores. As milled-samples are better described as if formed by nanometer-sized pyrochlore domains embedded in a fluorite-like matrix. Thermal annealing induces domain growth, so that the event observed by differential thermal analysis can be attributed to an evolution from medium to long-range pyrochlore ordering, typically from tens to hundreds of nanometers.

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Novel XAFS capabilities at ELETTRA synchrotron light source

Cited by 217 publications

References 18 publications

Advanced approach to the local structure reconstruction and theory validation on the example of the W L₃-edge extended x-ray absorption fine structure of tungsten

Advanced approach to the local structure reconstruction and theory validation on the example of the W L₃-edge extended x-ray absorption fine structure of tungsten

Local vibrational properties of GaAs studied by extended X-ray absorption fine structure

Raman and x-ray absorption spectroscopy study of the phase evolution induced by mechanical milling and thermal treatments inR2Ti2O
Sanjuán
¹
,
Guglieri
²
,
Díaz‐Moreno
³

et al. 2011
Phys. Rev. B
74
1
45
0
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Novel XAFS capabilities at ELETTRA synchrotron light source

Cited by 217 publications

References 18 publications

Advanced approach to the local structure reconstruction and theory validation on the example of the W L3-edge extended x-ray absorption fine structure of tungsten

Advanced approach to the local structure reconstruction and theory validation on the example of the W L3-edge extended x-ray absorption fine structure of tungsten

Local vibrational properties of GaAs studied by extended X-ray absorption fine structure

Raman and x-ray absorption spectroscopy study of the phase evolution induced by mechanical milling and thermal treatments inR2Ti2OSanjuán1, Guglieri2, Díaz‐Moreno3 et al. 2011Phys. Rev. B741450View full textAdd to dashboardCite

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Advanced approach to the local structure reconstruction and theory validation on the example of the W L₃-edge extended x-ray absorption fine structure of tungsten

Advanced approach to the local structure reconstruction and theory validation on the example of the W L₃-edge extended x-ray absorption fine structure of tungsten

Raman and x-ray absorption spectroscopy study of the phase evolution induced by mechanical milling and thermal treatments inR2Ti2O
Sanjuán
¹
,
Guglieri
²
,
Díaz‐Moreno
³

et al. 2011
Phys. Rev. B
74
1
45
0
View full text Add to dashboard Cite