Quantitative order‐parameter measurement in lattice‐mismatched AlInP using precession electron diffraction

2021 ◽  
Author(s):  
Xavier Pasala ◽  
Nikhil Pokharel ◽  
Phil Ahrenkiel ◽  
Kirstin Alberi ◽  
Kamran Forghani ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Order Parameter ◽  
Parameter Measurement ◽  
Precession Electron Diffraction

scholarly journals A complicated quasicrystal approximant ∊16 predicted by the strong-reflections approach

2010 ◽  
Vol 66 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Mingrun Li ◽  
Junliang Sun ◽  
Peter Oleynikov ◽  
Sven Hovmöller ◽  
Xiaodong Zou ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Unit Cell ◽  
Space Groups ◽  
Inverse Fourier Transformation ◽  
Transmission Electron ◽  
Structure Factors ◽  
Precession Electron Diffraction ◽  
Density Map ◽  
Electron Density Map ◽  
Good Agreement

The structure of a complicated quasicrystal approximant ∊16 was predicted from a known and related quasicrystal approximant ∊6 by the strong-reflections approach. Electron-diffraction studies show that in reciprocal space, the positions of the strongest reflections and their intensity distributions are similar for both approximants. By applying the strong-reflections approach, the structure factors of ∊16 were deduced from those of the known ∊6 structure. Owing to the different space groups of the two structures, a shift of the phase origin had to be applied in order to obtain the phases of ∊16. An electron-density map of ∊16 was calculated by inverse Fourier transformation of the structure factors of the 256 strongest reflections. Similar to that of ∊6, the predicted structure of ∊16 contains eight layers in each unit cell, stacked along the b axis. Along the b axis, ∊16 is built by banana-shaped tiles and pentagonal tiles; this structure is confirmed by high-resolution transmission electron microscopy (HRTEM). The simulated precession electron-diffraction (PED) patterns from the structure model are in good agreement with the experimental ones. ∊16 with 153 unique atoms in the unit cell is the most complicated approximant structure ever solved or predicted.

scholarly journals Towards Routine Structure Solution using Precession Electron Diffraction

2009 ◽  
Vol 15 (S2) ◽  
pp. 738-739
Author(s):  
PA Midgley ◽  
A Eggeman ◽  
T White ◽  
E Bithell
Keyword(s):  
Electron Diffraction ◽  
Structure Solution ◽  
Precession Electron Diffraction

Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009

Is precession electron diffraction kinematical? Part I:

2010 ◽  
Vol 110 (7) ◽  
pp. 763-770 ◽  
Author(s):  
T.A. White ◽  
A.S. Eggeman ◽  
P.A. Midgley
Keyword(s):  
Electron Diffraction ◽  
Precession Electron Diffraction

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 Crystallographic characterization of polycrystalline materials: High resolution automated crystallite orientation & phase mapping and Precession electron diffraction ring patterns

2010 ◽  
Vol 16 (S2) ◽  
pp. 768-769 ◽  
Author(s):  
S Rouvimov ◽  
P Moeck ◽  
E Rauch ◽  
Y Maniette ◽  
D Bultreys
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
Polycrystalline Materials ◽  
Crystallite Orientation ◽  
Diffraction Ring ◽  
Precession Electron Diffraction ◽  
Phase Mapping

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

Crystal Structures of Two Important Pharmaceuticals Solved by 3D Precession Electron Diffraction Tomography

2018 ◽  
Vol 22 (10) ◽  
pp. 1365-1372 ◽  
Author(s):  
Partha P. Das ◽  
Enrico Mugnaioli ◽  
Stavros Nicolopoulos ◽  
Camilla Tossi ◽  
Mauro Gemmi ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Crystal Structures ◽  
Diffraction Tomography ◽  
Precession Electron Diffraction
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