scholarly journals Towards routine structure solution using precession electron diffraction

2012 ◽  
Vol 68 (a1) ◽  
pp. s3-s3
Author(s):  
P. A. Midgley ◽  
A. S. Eggeman
Keyword(s):  
Electron Diffraction ◽  
Structure Solution ◽  
Precession Electron Diffraction

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

Strategies for full structure solution of intermetallic compounds using precession electron diffraction zonal data

2014 ◽  
Vol 47 (3) ◽  
pp. 1032-1041 ◽  
Author(s):  
Shmuel Samuha ◽  
Yaakov Krimer ◽  
Louisa Meshi
Keyword(s):  
Electron Diffraction ◽  
Intermetallic Compounds ◽  
Intermetallic Phase ◽  
Structure Type ◽  
Atomic Model ◽  
Coordination Polyhedra ◽  
Structure Solution ◽  
Precession Electron Diffraction ◽  
Full Structure ◽  
Merging Process

Owing to the individuality of intermetallic compounds, they are regarded as a special class of materials. As such, there is a need to develop a step-by-step methodology for solution of their structure. The current paper adapts the methodology of structure solution from precession electron diffraction (PED) zonal data for intermetallics. The optimization of PED parameters for structure determination was achieved through the development of the atomic model of a well known Mg17Al12(β) intermetallic phase. It was concluded that the PED acquisition parameters, the number of unique reflections and the quality of the merging process are the most important parameters that directly influence the correctness of a structure solution. The proposed methodology was applied to the structure solution of a highly complex new Mg48Al36Ag16phase, which was recently revealed in the Mg–Al–Ag system. The final atomic model consisted of 152 atoms in the unit cell, distributed over 23 unique atomic positions. The correctness of the atomic model was verified by the reasonability of the interatomic distances and coordination polyhedra formed. It was found that the experimental model of Φ-Al17.1Mg53.4Zn29.5can be assigned as a structure type for the Mg48Al36Ag16phase. The Δ value, which measures the similarity between two structures, was calculated as 0.040.

Direct space structure solution from precession electron diffraction data: Resolving heavy and light scatterers in Pb13Mn9O25

2010 ◽  
Vol 110 (7) ◽  
pp. 881-890 ◽  
Author(s):  
Joke Hadermann ◽  
Artem M. Abakumov ◽  
Alexander A. Tsirlin ◽  
Vladimir P. Filonenko ◽  
Julie Gonnissen ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Diffraction Data ◽  
Space Structure ◽  
Electron Diffraction Data ◽  
Structure Solution ◽  
Precession Electron Diffraction

The structure of nano-twinned rhombohedral YCuO2.66 solved by electron crystallography

2019 ◽  
Vol 75 (1) ◽  
pp. 107-112 ◽  
Author(s):  
Holger Klein ◽  
V. Ovidiu Garlea ◽  
Céline Darie ◽  
Pierre Bordet
Keyword(s):  
Electron Diffraction ◽  
Two Dimensions ◽  
Electron Diffraction Data ◽  
Electron Crystallography ◽  
One Dimensional ◽  
X Ray ◽  
Spin Interactions ◽  
Structure Solution ◽  
Precession Electron Diffraction ◽  
Frustrated Spin

In the search for frustrated spin interactions, a YCuO2.66 phase has been synthesized by a treatment under oxygen pressure of YCuO2.5. X-ray powder diffraction and electron diffraction studies have been conducted. Electron diffraction shows that the sample is twinned on a 10 nm scale. Precession electron diffraction data obtained from a twinned crystal was treated in order to obtain intensities corresponding to only one of the orientations of the twins. From this data a structure solution was obtained where, as in YCuO2.5, the Cu atoms form triangular planes. The Cu atoms are linked in two dimensions by oxygen atoms in the present structure whereas in YCuO2.5 they are only linked in one-dimensional chains.

Atomic structure solution of the complex quasicrystal approximant Al77Rh15Ru8from electron diffraction data

2014 ◽  
Vol 70 (6) ◽  
pp. 999-1005 ◽  
Author(s):  
Shmuel Samuha ◽  
Enrico Mugnaioli ◽  
Benjamin Grushko ◽  
Ute Kolb ◽  
Louisa Meshi
Keyword(s):  
Electron Diffraction ◽  
Structural Model ◽  
Direct Methods ◽  
High Resolution Electron Microscopy ◽  
Single Type ◽  
Electron Diffraction Data ◽  
Decagonal Quasicrystals ◽  
Resolution Electron ◽  
Structure Solution ◽  
Precession Electron Diffraction

The crystal structure of the novel Al77Rh15Ru8phase (which is an approximant of decagonal quasicrystals) was determined using modern direct methods (MDM) applied to automated electron diffraction tomography (ADT) data. The Al77Rh15Ru8E-phase is orthorhombic [Pbma,a= 23.40 (5),b= 16.20 (4) andc= 20.00 (5) Å] and has one of the most complicated intermetallic structures solved solely by electron diffraction methods. Its structural model consists of 78 unique atomic positions in the unit cell (19 Rh/Ru and 59 Al). Precession electron diffraction (PED) patterns and high-resolution electron microscopy (HRTEM) images were used for the validation of the proposed atomic model. The structure of the E-phase is described using hierarchical packing of polyhedra and a single type of tiling in the form of a parallelogram. Based on this description, the structure of the E-phase is compared with that of the ε6-phase formed in Al–Rh–Ru at close compositions.

Structure solution of the new titanate Li4Ti8Ni3O21 using precession electron diffraction

2009 ◽  
Vol 66 (1) ◽  
pp. 60-68 ◽  
Author(s):  
Mauro Gemmi ◽  
Holger Klein ◽  
Amelie Rageau ◽  
Pierre Strobel ◽  
Federic Le Cras
Keyword(s):  
Electron Diffraction ◽  
Three Dimensional ◽  
Direct Methods ◽  
Electron Diffraction Experiment ◽  
Cation Site ◽  
Synchrotron Powder Diffraction ◽  
Edge Sharing Octahedra ◽  
Structure Solution ◽  
Precession Electron Diffraction ◽  
Trigonal Phase

A sample having stoichiometry Li[Ti1.5Ni0.5]O4 has been synthesized to obtain a spinel structure. The resulting crystalline powder revealed a multiphase nature with spinel as the minor phase. The main phase is a new trigonal phase having a = 5.05910 (1), c = 32.5371 (1) Å. The structure has been solved by direct methods working on a three-dimensional set of intensities obtained from a precession electron-diffraction experiment, and refined on synchrotron powder diffraction data in the space group P\bar 3c1. The model consists of hexagonal layers of edge-sharing octahedra occupied either by the heavy cations Ti and Ni, or preferentially by Li. On the basis of cation-site occupancies the stoichiometry becomes Li4Ti8Ni3O21, which is compatible with the microanalysis results.

scholarly journals Combining precession electron diffraction data with X-ray powder diffraction data to facilitate structure solution

2008 ◽  
Vol 41 (6) ◽  
pp. 1115-1121 ◽  
Author(s):  
Dan Xie ◽  
Christian Baerlocher ◽  
Lynne B. McCusker
Keyword(s):  
Electron Diffraction ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Electron Diffraction Data ◽  
Powder Diffraction Data ◽  
Powder Charge ◽  
X Ray ◽  
Structure Solution ◽  
Precession Electron Diffraction ◽  
Using Data

Information derived from precession electron diffraction (PED) patterns can be used to advantage in combination with high-resolution X-ray powder diffraction data to solve crystal structures that resist solution from X-ray data alone. PED data have been exploited in two different ways for this purpose: (1) to identify weak reflections and (2) to estimate the phases of the reflections in the projection. The former is used to improve the partitioning of the reflection intensities within an overlap group and the latter to provide some starting phases for structure determination. The information was incorporated into a powder charge-flipping algorithm for structure solution. The approaches were first developed using data for the moderately complex zeolite ZSM-5, and then tested on TNU-9, one of the two most complex zeolites known. In both cases, including PED data from just a few projections facilitated structure solution significantly.

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