Understanding the properties of energy materials from their local structure

Atomic pair distribution function (PDF) analysis has been widely used to investigate nanocrystalline and structurally disordered materials. Experimental PDFs retrieved from electron diffraction (ePDF) in transmission electron microscopy (TEM) represent an attractive alternative to traditional PDF obtained from synchrotron X-ray sources, when employed on minute samples. Nonetheless, the inelastic scattering produced by the large dynamical effects of electron diffraction may obscure the interpretation of ePDF. In the present work, precession electron diffraction (PED-TEM) has been employed to obtain the ePDF of two different sub-monolayer samples ––lipoic acid protected (~ 4.5 nm) and hexanethiolated(~ 4.2 nm, ~ 400-kDa core mass) gold nanoparticles––randomly oriented and measured at both liquid-nitrogen and room temperatures, with high dynamic-range detection of a CMOS camera. The electron diffraction data were processed to obtain ePDFs which were subsequently compared with PDF of different ideal structure-models. The results demonstrate that the PED-ePDF data is sensitive to different crystalline structures such as monocrystalline (truncated octahedra) versus multiply-twinned (decahedra, icosahedra) structuresof the face-centered cubic gold lattice. The results indicate that PED reduces the residual from 46% to 29%; in addition, the combination of PED and low temperature further reduced the residual to 23%, which is comparable to X-ray PDF analysis. Furthermore, the inclusion of PED resulted in a better estimation of the coordination number from ePDF. To the best of our knowledge, the precessed electron-beam technique (PED) has not been previously applied to nanoparticles for analysis by the ePDF method.

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Local structural studies on Co doped ZnS nanowires by synchrotron X-ray atomic pair distribution function and micro-Raman shift

RSC Advances ◽

10.1039/c7ra02668d ◽

2017 ◽

Vol 7 (59) ◽

pp. 37402-37411 ◽

Cited By ~ 8

Author(s):

U. P. Gawai ◽

B. N. Dole

Keyword(s):

Distribution Function ◽

Pair Distribution Function ◽

Function Analysis ◽

Scattering Data ◽

Raman Shift ◽

X Ray ◽

Atomic Structures ◽

Atomic Pair Distribution Function ◽

X Ray Scattering ◽

Atomic Pair

The atomic structures of nanowires were studied by X-ray atomic pair distribution function analysis and total synchrotron X-ray scattering data. A PDF method was used to describe a wurtzite and zinc-blended mixed phase model.

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High-energy X-ray powder diffraction and atomic-pair distribution-function studies of charged/discharged structures in carbon-hybridized Li2MnSiO4 nanoparticles as a cathode material for lithium-ion batteries

Journal of Power Sources ◽

10.1016/j.jpowsour.2014.03.065 ◽

2014 ◽

Vol 263 ◽

pp. 7-12 ◽

Cited By ~ 11

Author(s):

Maki Moriya ◽

Masahiko Miyahara ◽

Mana Hokazono ◽

Hirokazu Sasaki ◽

Atsushi Nemoto ◽

...

Keyword(s):

Distribution Function ◽

Cathode Material ◽

Lithium Ion Batteries ◽

Powder Diffraction ◽

Pair Distribution Function ◽

Lithium Ion ◽

High Energy ◽

X Ray ◽

Atomic Pair Distribution Function ◽

Atomic Pair

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Exact and explicit expression of the atomic pair distribution function as obtained from X-ray total scattering experiments

Journal of Applied Crystallography ◽

10.1107/s0021889812051357 ◽

2013 ◽

Vol 46 (2) ◽

pp. 461-465 ◽

Cited By ~ 11

Author(s):

Olivier Masson ◽

Philippe Thomas

Keyword(s):

Distribution Function ◽

Explicit Expression ◽

Pair Distribution Function ◽

Structural Information ◽

Functional Materials ◽

X Rays ◽

Total Scattering ◽

X Ray ◽

Atomic Pair Distribution Function ◽

Atomic Pair

The atomic pair distribution function (PDF) as obtained from X-ray or neutron total scattering experiments has proved to be powerful in obtaining valuable structural information for many complex functional materials, be they amorphous or crystalline. In the case of measurements made with X-rays and for samples containing more than one kind of atom, the usefulness of the PDF is, however, somewhat hampered because of the lack of an exact and simple expression relating it to the structure of the materials. Only an approximate relationship exits, which is still in use today. This is particularly detrimental given the wide availability of X-ray sources and the increasing quality of PDFs obtained with laboratory sources. In this paper, the exact and explicit expression of the PDF as obtained from X-ray scattering is derived with respect to partial functions. This expression allows exact and efficient calculation of the PDF from any structure model without using approximate formulae.

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Local atomic structure of thin and ultrathin films via rapid high-energy X-ray total scattering at grazing incidence

IUCrJ ◽

10.1107/s2052252519000514 ◽

2019 ◽

Vol 6 (2) ◽

pp. 290-298 ◽

Cited By ~ 11

Author(s):

Ann-Christin Dippel ◽

Martin Roelsgaard ◽

Ulrich Boettger ◽

Theodor Schneller ◽

Olof Gutowski ◽

...

Keyword(s):

Thin Film ◽

Ultrathin Films ◽

Grazing Incidence ◽

High Energy ◽

X Ray ◽

Rapid Acquisition ◽

Atomic Pair Distribution Function ◽

Atomic Pair ◽

Pdf Analysis ◽

Incidence Geometries

Atomic pair distribution function (PDF) analysis is the most powerful technique to study the structure of condensed matter on the length scale from short- to long-range order. Today, the PDF approach is an integral part of research on amorphous, nanocrystalline and disordered materials from bulk to nanoparticle size. Thin films, however, demand specific experimental strategies for enhanced surface sensitivity and sophisticated data treatment to obtain high-quality PDF data. The approach described here is based on the surface high-energy X-ray diffraction technique applying photon energies above 60 keV at grazing incidence. In this way, reliable PDFs were extracted from films of thicknesses down to a few nanometres. Compared with recently published reports on thin-film PDF analysis from both transmission and grazing-incidence geometries, this work brought the minimum detectable film thickness down by about a factor of ten. Depending on the scattering power of the sample, the data acquisition on such ultrathin films can be completed within fractions of a second. Hence, the rapid-acquisition grazing-incidence PDF method is a major advancement in thin-film technology that opens unprecedented possibilities for in situ and operando PDF studies in complex sample environments. By uncovering how the structure of a layered material on a substrate evolves and transforms in terms of local and average ordering, this technique offers new opportunities for understanding processes such as nucleation, growth, morphology evolution, crystallization and the related kinetics on the atomic level and in real time.

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Chemical short range order obtained from the atomic pair distribution function

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1524/zkri.217.2.47.20626 ◽

2002 ◽

Vol 217 (2) ◽

Cited By ~ 26

Author(s):

Th. Proffen ◽

V. Petkov ◽

S. J. L. Billinge ◽

T. Vogt

Keyword(s):

Distribution Function ◽

Pair Distribution Function ◽

Short Range ◽

Short Range Order ◽

Structural Information ◽

Range Order ◽

Crystalline Materials ◽

X Ray ◽

Atomic Pair Distribution Function ◽

Atomic Pair

AbstractMany crystalline materials show chemical short range order and relaxation of neighboring atoms. Local structural information can be obtained by analyzing the atomic pair distribution function (PDF) obtained from powder diffraction data. In this paper, we present the successful extraction of chemical short range order parameters from the x-ray PDF of a quenched Cu

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Structural Analysis of Ligand Protected Smaller Metallic Nanocrystals by Atomic Pair Distribution Function Under Precession Electron Diffraction

10.26434/chemrxiv.8859572 ◽

2019 ◽

Author(s):

M. Mozammel Hoque ◽

Sandra Vergara ◽

Partha P. Das ◽

Daniel Ugarte ◽

Ulises Santiago ◽

...

Keyword(s):

Distribution Function ◽

Electron Diffraction ◽

Pair Distribution Function ◽

Electron Diffraction Data ◽

Face Centered Cubic ◽

X Ray ◽

Atomic Pair Distribution Function ◽

Atomic Pair ◽

Pdf Analysis ◽

Precession Electron Diffraction

Atomic pair distribution function (PDF) analysis has been widely used to investigate nanocrystalline and structurally disordered materials. Experimental PDFs retrieved from electron diffraction (ePDF) in transmission electron microscopy (TEM) represent an attractive alternative to traditional PDF obtained from synchrotron X-ray sources, when employed on minute samples. Nonetheless, the inelastic scattering produced by the large dynamical effects of electron diffraction may obscure the interpretation of ePDF. In the present work, precession electron diffraction (PED-TEM) has been employed to obtain the ePDF of two different sub-monolayer samples ––lipoic acid protected (~ 4.5 nm) and hexanethiolated(~ 4.2 nm, ~ 400-kDa core mass) gold nanoparticles––randomly oriented and measured at both liquid-nitrogen and room temperatures, with high dynamic-range detection of a CMOS camera. The electron diffraction data were processed to obtain ePDFs which were subsequently compared with PDF of different ideal structure-models. The results demonstrate that the PED-ePDF data is sensitive to different crystalline structures such as monocrystalline (truncated octahedra) versus multiply-twinned (decahedra, icosahedra) structuresof the face-centered cubic gold lattice. The results indicate that PED reduces the residual from 46% to 29%; in addition, the combination of PED and low temperature further reduced the residual to 23%, which is comparable to X-ray PDF analysis. Furthermore, the inclusion of PED resulted in a better estimation of the coordination number from ePDF. To the best of our knowledge, the precessed electron-beam technique (PED) has not been previously applied to nanoparticles for analysis by the ePDF method.

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A statistical approach to correct X-ray response non-uniformity in microstrip detectors for high-accuracy and high-resolution total-scattering measurements

Journal of Synchrotron Radiation ◽

10.1107/s1600577519002145 ◽

2019 ◽

Vol 26 (3) ◽

pp. 762-773 ◽

Cited By ~ 5

Author(s):

Kenichi Kato ◽

Yoshihito Tanaka ◽

Miho Yamauchi ◽

Koji Ohara ◽

Takaki Hatsui

Keyword(s):

Poisson Noise ◽

Scattering Data ◽

Total Scattering ◽

X Ray ◽

Atomic Pair Distribution Function ◽

Atomic Pair ◽

Ni Powder ◽

Alternative Approach ◽

Microstrip Detectors

An unbiased approach to correct X-ray response non-uniformity in microstrip detectors has been developed based on the statistical estimation that the scattering intensity at a fixed angle from an object is expected to be constant within the Poisson noise. Raw scattering data of SiO2 glass measured by a microstrip detector module was found to show an accuracy of 12σPN at an intensity of 106 photons, where σPN is the standard deviation according to the Poisson noise. The conventional flat-field calibration has failed in correcting the data, whereas the alternative approach used in this article successfully improved the accuracy from 12σPN to 2σPN. This approach was applied to total-scattering data measured by a gapless 15-modular detector system. The quality of the data is evaluated in terms of the Bragg reflections of Si powder, the diffuse scattering of SiO2 glass, and the atomic pair distribution function of TiO2 nanoparticles and Ni powder.

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