Structure of nanocrystalline GaN from X-ray diffraction, Rietveld and atomic pair distribution function analyses

2005 ◽  
Vol 15 (43) ◽  
pp. 4654 ◽  
Author(s):  
V. Petkov ◽  
M. Gateshki ◽  
J. Choi ◽  
E. G. Gillan ◽  
Y. Ren
Keyword(s):  
Distribution Function ◽  
Pair Distribution Function ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Pair Distribution Function ◽  
Atomic Pair

THE ANALYSIS OF THE ATOMIC PAIR DISTRIBUTION FUNCTION OF PMN-BASED NANOPOWDERS BY X-RAY DIFFRACTION

2012 ◽  
Vol 26 (18) ◽  
pp. 1250118 ◽  
Author(s):  
M. GHASEMIFARD ◽  
GH. H. KHORRAMI
Keyword(s):  
Distribution Function ◽  
Pair Distribution Function ◽  
Three Dimensional ◽  
Ferroelectric Material ◽  
Atomic Scale ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Pair Distribution Function ◽  
Atomic Pair ◽  
Perovskite Type

The three-dimensional atomic-scale structure around Mg , Nb , Ti and Zr atoms in a series ferroelectric material such as PMN, PZT, PMN-PZT and PMN-PT has been studied using X-ray diffraction ( MoK α), Rietveld refinement and the atomic pair distribution function (PDF) technique. The structure and particle size of the powders was determined by X-ray diffraction and TEM observation. The studies show that the materials are disordered at nanometer length distances. The three-dimensional atomic ordering in PMN-based nanopowders may well be described by a cubic structure of the perovskite type, similar to that occurring in the bulk crystals. At the end, the analyzed data show that the sizes of ZrO 6 octahedral are larger than TiO 6 octahedral.

The Study of Local Structure of Amorphous Fe-Co-B-Si-Nb Alloy by Atomic Pair Distribution Function

2013 ◽  
Vol 203-204 ◽  
pp. 386-389 ◽  
Author(s):  
Wirginia Pilarczyk ◽  
Jacek Podwórny
Keyword(s):  
Distribution Function ◽  
Pair Distribution Function ◽  
Amorphous State ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Pair Distribution Function ◽  
Atomic Pair ◽  
Rapidly Solidified ◽  
Pressure Die Casting

The materials from Fe-Co-B-Si-Nb system have several interesting and useful properties such as high mechanical strength, abrasive and corrosion resistance and good electrical properties useful in many applications, for example: materials for sensors and precise current transformers. The aim of the presented work was to obtain Fe-based alloy in an amorphous state and examination atoms arrangement in its structure which has an influence on material properties. Multicomponent alloy with nominal composition of Fe37.44Co34.56B19.2Si4.8Nb4 was obtained by pressure die casting method in form of plate with thickness of d=1mm. The structure of rapidly solidified plate was examined by X-ray diffraction. This investigation revealed that the studied sample was amorphous. Based on experimental X-ray data the pair distribution function was calculated and discussion on possible atoms arrangement was carried out.

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.

A study of nanostructured ZnS polymorphs by synchrotron X-ray diffraction and atomic pair distribution function

RSC Advances ◽  
2016 ◽  
Vol 6 (56) ◽  
pp. 50479-50486 ◽  
Author(s):  
U. P. Gawai ◽  
H. A. Khawal ◽  
M. R. Bodke ◽  
K. K. Pandey ◽  
U. P. Deshpande ◽  
...  
Keyword(s):  
Distribution Function ◽  
Pair Distribution Function ◽  
Atomic Scale ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Pair Distribution Function ◽  
Atomic Pair ◽  
Scale Structures ◽  
Potential Tool

The combination of SCXRD and atomic PDF is a potential tool for the standardization of atomic scale structures of nanomaterials. This article describes the essential approach and application to ZnS polymorphs.

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.

Sign in / Sign up

Export Citation Format

Share Document