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

2019 ◽  
Vol 26 (3) ◽  
pp. 762-773 ◽  
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.

scholarly journals Understanding the properties of energy materials from their local structure

2014 ◽  
Vol 70 (a1) ◽  
pp. C860-C860
Author(s):  
Hyunjeong Kim
Keyword(s):  
Structural Information ◽  
Lithium Ion ◽  
Structural Features ◽  
Scattering Data ◽  
Energy Materials ◽  
X Ray ◽  
Atomic Pair Distribution Function ◽  
Structure Probing ◽  
Atomic Pair ◽  
Pdf Analysis

Numerous energy materials with improved properties often show nano- or heavily disordered structural features which are hardly characterized by the conventional crystallographic technique alone. By using the atomic pair distribution function (PDF) analysis [1]on X-ray and neutron total scattering data, we have investigated various energy materials to elucidate structural features closely linked to their properties. Some of the examples are heavily disordered V1-xTixH2 for hydrogen storage [2] and layered Li1.2Mn0.567Ni0.166Co0.067O2 cathode material for lithium ion batteries. These materials possess an intricate structure and could easily lead to misleading results if one relies on only one structure probing technique. In this talk, I will show how their structural information was extracted from the x-ray and neutron PDFs obtained at BL22XU at SPring-8 and NOVA at J-PARC, respectively and how it was used with information available from other techniques to understand the properties of these energy materials.

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

RSC Advances ◽  
2017 ◽  
Vol 7 (59) ◽  
pp. 37402-37411 ◽  
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.

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

2013 ◽  
Vol 46 (2) ◽  
pp. 461-465 ◽  
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.

scholarly journals Atomic pair distribution function at the Brazilian Synchrotron Light Laboratory: application to the Pb1–xLaxZr0.40Ti0.60O3ferroelectric system

2017 ◽  
Vol 24 (5) ◽  
pp. 1098-1104 ◽  
Author(s):  
M. E. Saleta ◽  
M. Eleotério ◽  
A. Mesquita ◽  
V. R. Mastelaro ◽  
E. Granado
Keyword(s):  
Distribution Function ◽  
Pair Distribution Function ◽  
X Ray Diffraction ◽  
Total Scattering ◽  
X Ray ◽  
Atomic Pair Distribution Function ◽  
Atomic Pair ◽  
Synchrotron Light ◽  
Photon Source

This work reports the setting up of the X-ray diffraction and spectroscopy beamline at the Brazilian Synchrotron Light Laboratory for performing total scattering experiments to be analyzed by atomic pair distribution function (PDF) studies. The results of a PDF refinement for Al2O3standard are presented and compared with data acquired at a beamline of the Advanced Photon Source, where it is common to perform this type of experiment. A preliminary characterization of the Pb1–xLaxZr0.40Ti0.60O3ferroelectric system, withx= 0.11, 0.12 and 0.15, is also shown.

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

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.

scholarly journals The atomic structure of a MgCo2O4 nanoparticle for a positive electrode of a Mg rechargeable battery

2019 ◽  
Vol 55 (17) ◽  
pp. 2517-2520 ◽  
Author(s):  
Naoto Kitamura ◽  
Yuhei Tanabe ◽  
Naoya Ishida ◽  
Yasushi Idemoto
Keyword(s):  
Monte Carlo ◽  
Atomic Structure ◽  
Positive Electrode ◽  
Scattering Data ◽  
Rechargeable Battery ◽  
Reverse Monte Carlo ◽  
Spinel Type ◽  
Total Scattering ◽  
X Ray ◽  
Neutron Total Scattering

The atomic structure of a spinel-type MgCo2O4 nanoparticle was investigated by the reverse Monte Carlo modelling using X-ray and neutron total scattering data.

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