Comparison of extended x-ray absorption fine structure and Scherrer analysis of x-ray diffraction as methods for determining mean sizes of polydisperse nanoparticles

Calvin, S.; Luo, Shuangling; Caragianis-Broadbridge, Christine; McGuinness, J. K.; Anderson, Everett B.; Lehman, A.; Wee, K. H.; Morrison, Shannon; Kurihara, Lynn K.

doi:10.1063/1.2137872

Cited by 79 publications

(73 citation statements)

References 12 publications

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“…from 46% to 100% in relative measure. This result was consistent with the approximate formula for spherical clusters given by Calvin et al [30]. The value 6.572 neighbours found in EXAFS modelling for both thin films suggested very small clusters (diameter 1-2 nm, less than 100 Ce atoms).…”

Section: Resultssupporting

confidence: 80%

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Structural and electrochemical investigations of Ce/Cu mixed oxide thin films

Škofic¹,

Gomilšek

Pihlar³

et al. 2011

Solar Energy Materials and Solar Cells

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a b s t r a c tThin films of Ce/Cu mixed oxide with molar ratios of 1 and 2 were prepared from inorganic precursors using the sol-gel route. Various electrochemical and spectroscopic techniques were used for characterization of the films and investigation of their optical and electrochemical properties. It was found that the redox behaviour significantly depends on the Ce/Cu ratio and on the concentration of Li + ions. Slow kinetics of the charge transfer reactions was evident from cyclic voltammetry measurements of both types of films only at low scan rates (o 20 mV/s). Measurement of X-ray absorption fine structure (XAFS) indicated that the local structure of Ce and Cu ions is not affected by the Ce/Cu molar ratio.

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Section: Resultssupporting

confidence: 80%

“…5. The average number of first Ce neighbours vs. cluster diameter for spherical clusters as counted from the list of atom sites (dots) and calculated by Calvin's formula [30] (solid line). The EXAFS best fit value and uncertainty region for the thin film samples are marked with solid and dotted horizontal lines, respectively.…”

Section: Resultsmentioning

confidence: 99%

Structural and electrochemical investigations of Ce/Cu mixed oxide thin films

Škofic¹,

Gomilšek

Pihlar³

et al. 2011

Solar Energy Materials and Solar Cells

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“…Such estimates depend on the shape of the model particle and are generally regarded as lower-bound estimates: for our q values and a spherical particle model, they are given in Table 2. The values are consistently smaller than the Debye-Scherrer estimates for a factor between 1.5 and 3; the relation between the different size estimates has been comprehensively discussed by Calvin et al (2005).…”

Section: Discussionmentioning

confidence: 95%

“…The particle sizes obtained from XRD-peak broadening are listed in Table 1. These values, although known to overshoot the average size systematically (Calvin et al 2005), will be used throughout this article for characterization of nanoparticles. Another lower estimate will be obtained below from EXAFS data.…”

Section: Resultsmentioning

confidence: 99%

Structure of manganese zinc ferrite spinel nanoparticles prepared with co-precipitation in reversed microemulsions

et al. 2008

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The structure of Mn 0.5 Zn 0.5 Fe 2 O 4 spinel ferrite nanoparticles is studied as a function of their size and the experimental conditions of their synthesis using X-ray absorption spectroscopy. The nanoparticles of different sizes down to approximately 2 nm and with a narrow size distribution were synthesized using co-precipitation in reverse microemulsions. Simultaneous refinement of the X-ray absorption fine structure (EXAFS) of three constituting metals shows a migration of Mn and Zn ions to the octahedral site of the spinel lattice compensated by the corresponding migration of the Fe ions. To a smaller extent, Mn ions switch the occupation site already in bulk and in larger nanoparticles, while a sporadic migration of Zn is detected only in the nanoparticles with sizes below approximately 5 nm. X-ray absorption near edge structure (XANES) reveals considerable variations in the position of the Mn K edge, suggesting the average Mn valence in the nanoparticles to be higher than 3?. Annealing at 500°C relaxes the structure of as-synthesized nanoparticles toward the structure of the ceramic bulk standard.

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“…Isochronal annealing was carried out by warming the sample to a series of higher temperatures (T A = 35, 45,55,65,75,95,105,115,125,135,156,200, and 300 K), holding at that temperature for 5 minutes, then cooling back down to 15 K for EXAFS measurements. Heating to and cooling from the T A = 35 K took less than 10 minutes, rising to around 2 hours each direction for the T A = 300 K. Although the EXAFS for each data point for each edge took approximately 1 hour to collect, the measurements lasted over 2.5 days of beamtime due to extra time spent heating and cooling.…”

Section: Methodsmentioning

confidence: 99%

Isochronal annealing effects on local structure, crystalline fraction, and undamaged region size of radiation damage in Ga-stabilized δ-Pu

Olive

Wang

Booth

et al. 2016

Journal of Applied Physics

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The effects on the local structure due to self-irradiation damage of Ga stabilized δ-Pu stored at cryogenic temperatures have been examined using extended x-ray absorption fine structure (EXAFS) experiments. Extensive damage, seen as a loss of local order, was evident after 72 days of storage below 15 K. The effect was observed from both the Pu and Ga sites, although less pronounced around Ga. Isochronal annealing was performed on this sample to study the annealing processes that occur between cryogenic and room temperature storage conditions, where damage is mostly reversed. Damage fractions at various points along the annealing curve have been determined using an amplitude-ratio method, standard EXAFS fitting, and a spherical crystallite model, and provide information complementary to previous electrical resistivity-and susceptibility-based isochronal annealing studies. The use of a spherical crystallite model accounts for the changes in EXAFS spectra using just two parameters, namely, the crystalline fraction and the particle radius. Together, these results are discussed in terms of changes to the local structure around Ga and Pu throughout the annealing process and highlight the unusual role of Ga in the behavior of the lowest temperature anneals.

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Comparison of extended x-ray absorption fine structure and Scherrer analysis of x-ray diffraction as methods for determining mean sizes of polydisperse nanoparticles

Cited by 79 publications

References 12 publications

Structural and electrochemical investigations of Ce/Cu mixed oxide thin films

Structural and electrochemical investigations of Ce/Cu mixed oxide thin films

Structure of manganese zinc ferrite spinel nanoparticles prepared with co-precipitation in reversed microemulsions

Isochronal annealing effects on local structure, crystalline fraction, and undamaged region size of radiation damage in Ga-stabilized δ-Pu

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