Structure analysis of titanate nanorods by automated electron diffraction tomography

2011 ◽  
Vol 67 (3) ◽  
pp. 218-225 ◽  
Author(s):  
Iryna Andrusenko ◽  
Enrico Mugnaioli ◽  
Tatiana E. Gorelik ◽  
Dominik Koll ◽  
Martin Panthöfer ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Sodium Titanate ◽  
Electron Diffraction Data ◽  
Monoclinic Space Group ◽  
Diffraction Tomography ◽  
X Ray ◽  
Unknown Phase ◽  
Transmission Electron ◽  
Edge Dislocations ◽  
New Phase

A hitherto unknown phase of sodium titanate, NaTi3O6(OH)·2H2O, was identified as the intermediate species in the synthesis of TiO2 nanorods. This new phase, prepared as nanorods, was investigated by electron diffraction, X-ray powder diffraction, thermogravimetric analysis and high-resolution transmission electron microscopy. The structure was determined ab initio using electron diffraction data collected by the recently developed automated diffraction tomography technique. NaTi3O6(OH)·2H2O crystallizes in the monoclinic space group C2/m. Corrugated layers of corner- and edge-sharing distorted TiO6 octahedra are intercalated with Na+ and water of crystallization. The nanorods are typically affected by pervasive defects, such as mutual layer shifts, that produce diffraction streaks along c*. In addition, edge dislocations were observed in HRTEM images.

X-ray powder diffraction and transmission electron diffraction data for BaMnSi2O6—A new phase in the system BaO–MnO–SiO2

1996 ◽  
Vol 11 (4) ◽  
pp. 284-287 ◽  
Author(s):  
I. T. Ivanov ◽  
D. D. Nihtianova ◽  
I. Georgieva
Keyword(s):  
Electron Diffraction ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Electron Diffraction Data ◽  
Space Group ◽  
X Ray ◽  
Transmission Electron ◽  
New Phase

A new phase in the system BaO–MnO–SiO2 obtained by a pyrosynthetic method has been inves- tigated using electron microprobe analysis (EPMA), X-ray powder diffraction (PDA), and trans- mission electron diffraction. The lattice parameters and possible space group of the phase with a general composition BaMnSi2O6 were determined as follows: a=13.896, b=12.261, c=10.781 Å, β=103.47°, space group P21/m, Z=12.

Transmission Electron Microscopy Studies of 5-cycled Na Alanate with Ti Based Additive

2005 ◽  
Vol 884 ◽  
Author(s):  
Carmen M. Andrei ◽  
John C. Walmsley ◽  
Randi Holmestad ◽  
Gianluigi A. Botton ◽  
Sesha S. Srinivasan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Hydrogen Storage Material ◽  
Hydrogen Diffusivity ◽  
Storage Material ◽  
X Ray ◽  
Transmission Electron ◽  
Edge Dislocations

AbstractTi doped NaAlH4 hydride is proposed as a reversible hydrogen storage material. In this work, the microstructure of NaAlH4 with 2% TiCl3 additive was studied after 5 hydrogen cycles using a combination of transmission electron microscopy (TEM) techniques including energy dispersive spectroscopy (EDS) X-ray analysis. Selected area diffraction and high-resolution (HR) imaging confirmed the presence of the NaH phase in the material. Electron diffraction was dominated by Al. HRTEM showed the presence of edge dislocations, which might influence the hydrogen diffusivity process in these materials.

Structural insights intoM2O–Al2O3–WO3(M= Na, K) system by electron diffraction tomography

2015 ◽  
Vol 71 (3) ◽  
pp. 349-357 ◽  
Author(s):  
Iryna Andrusenko ◽  
Yaşar Krysiak ◽  
Enrico Mugnaioli ◽  
Tatiana E. Gorelik ◽  
Diana Nihtianova ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Three Dimensional ◽  
Large Cell ◽  
Systematic Investigation ◽  
Electron Diffraction Data ◽  
Diffraction Tomography ◽  
Structure Investigation ◽  
X Ray ◽  
Cell Parameters ◽  
Wide Range

TheM2O–Al2O3–WO3(M= alkaline metals) system has attracted the attention of the scientific community because some of its members showed potential applications as single crystalline media for tunable solid-state lasers. These materials behave as promising laser host materials due to their high and continuous transparency in the wide range of the near-IR region. A systematic investigation of these phases is nonetheless hampered because it is impossible to produce large crystals and only in a few cases a pure synthetic product can be achieved. Despite substantial advances in X-ray powder diffraction methods, structure investigation on nanoscale is still challenging, especially when the sample is polycrystalline and the structures are affected by pseudo-symmetry. Electron diffraction has the advantage of collecting data from single nanoscopic crystals, but it is frequently limited by incompleteness and dynamical effects. Automated diffraction tomography (ADT) recently emerged as an alternative approach able to collect more complete three-dimensional electron diffraction data and at the same time to significantly reduce dynamical scattering. ADT data have been shown to be suitable forabinitiostructure solution of phases with large cell parameters, and for detecting pseudo-symmetry that was undetected in X-ray powder data. In this work we present the structure investigation of two hitherto undetermined compounds, K5Al(W3O11)2and NaAl(WO4)2, by a combination of electron diffraction tomography and precession electron diffraction. We also stress how electron diffraction tomography can be used to obtain direct information about symmetry and pseudo-symmetry for nanocrystalline phases, even when available only in polyphasic mixtures.

scholarly journals MicroED: a versatile cryoEM method for structure determination

2018 ◽  
Vol 2 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Brent L. Nannenga ◽  
Tamir Gonen
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Electron Diffraction ◽  
Structure Determination ◽  
Materials Science ◽  
Electron Diffraction Data ◽  
Determination Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Micro-electron diffraction, or MicroED, is a structure determination method that uses a cryo-transmission electron microscope to collect electron diffraction data from nanocrystals. This technique has been successfully used to determine the high-resolution structures of many targets from crystals orders of magnitude smaller than what is needed for X-ray diffraction experiments. In this review, we will describe the MicroED method and recent structures that have been determined. Additionally, applications of electron diffraction to the fields of small molecule crystallography and materials science will be discussed.

On the Determination of Partial RDFs for Amorphous Materials

1993 ◽  
Vol 321 ◽  
Author(s):  
L. C. Qin ◽  
L. W. Hobbs
Keyword(s):  
Electron Diffraction ◽  
Diffraction Data ◽  
Amorphous Materials ◽  
Vitreous Silica ◽  
Scanning Transmission Electron Microscope ◽  
Distribution Functions ◽  
Electron Diffraction Data ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission

ABSTRACTRadial distribution functions (RDFs) for vitreous silica (V-SiO2) have been obtained from energy-filtered electron diffraction data obtained in the HB5 scanning transmission electron Microscope. Results have been compared with those obtained from high-resolution neutron diffraction experiments, and are in good agreement within experimental errors. It was found to be impractical to obtain partial RDFs for this material from combined neutron, X-ray and electron diffraction data, because the similarities in characteristics of X-ray and electron scattering cause indeter-Minacies. A criterion equation has been given to determine feasibility.

scholarly journals Quantitative Electron Diffraction Data of Amorphous Materials

2005 ◽  
Vol 60 (6) ◽  
pp. 459-468 ◽  
Author(s):  
Jürgen Ankele ◽  
Joachim Mayer ◽  
Peter Lamparter ◽  
Siegfried Steeb
Keyword(s):  
Electron Diffraction ◽  
Multiple Scattering ◽  
Diffraction Data ◽  
Amorphous Materials ◽  
Structural Model ◽  
Electron Diffraction Data ◽  
X Ray ◽  
A Value ◽  
Transmission Electron ◽  
Scattering Correction

A method has been developed to obtain quantitative electron diffraction data up to a value of Q = 20 Å−1 of the modulus of the scattering vector. The experiments were performed on a commercially available transmission electron microscope equipped with a so-called omega energy filter. An analytical multiple scattering correction was applied. The electron diffraction results obtained with amorphous germanium were compared with X-ray and neutron diffraction data and showed good agreement. For an amorphous Ni63Nb37 sample it was shown that it is possible to estimate the multiple scattering intensity without exact knowledge of the sample thickness. This technique was applied to derive the structure factor for electron diffraction of two precursor-derived amorphous Si-C-N ceramics (a-Si24C43N33 and a-Si40C24N36). The results are consistent with corresponding X-ray diffraction data and with an existing structural model for such ceramics.

Direct Methods for Surfaces

1998 ◽  
Vol 05 (05) ◽  
pp. 1087-1106 ◽  
Author(s):  
L. D. Marks ◽  
E. Bengu ◽  
C. Collazo-Davila ◽  
D. Grozea ◽  
E. Landree ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Mathematical Theory ◽  
Recent Progress ◽  
Direct Methods ◽  
Surface Structures ◽  
Electron Diffraction Data ◽  
X Ray ◽  
Experimental Systems ◽  
Transmission Electron ◽  
Basic Ideas

This paper reviews recent progress in the application of Direct Methods to solve surface structures using surface X-ray or transmission electron diffraction data. The basic ideas of (crystallographic) Direct Methods are presented, as well as the additional problems posed by trying to apply them to surfaces and how they connect to the mathematical theory of projections. Surface crystallography notation is presented, which differs from the widely used LEED notation in that it emphasizes the surface symmetry. This is followed by a description of methods for structure completion and refinement, followed by applications to some experimental systems, both those where the structure was previously known (calibration tests) and a few where it was not, concluding with problems and limitations.

scholarly journals Automated electron diffraction tomography – development and applications

2019 ◽  
Vol 75 (4) ◽  
pp. 463-474 ◽  
Author(s):  
Ute Kolb ◽  
Yaşar Krysiak ◽  
Sergi Plana-Ruiz
Keyword(s):  
Electron Diffraction ◽  
Structure Analysis ◽  
Three Dimensional ◽  
Crystal Structure Analysis ◽  
Electron Diffraction Data ◽  
Diffraction Tomography ◽  
Established Method ◽  
General Applicability ◽  
Transmission Electron ◽  
Electron Microscopes

Electron diffraction tomography (EDT) has gained increasing interest, starting with the development of automated electron diffraction tomography (ADT) which enables the collection of three-dimensional electron diffraction data from nano-sized crystals suitable for ab initio structure analysis. A basic description of the ADT method, nowadays recognized as a reliable and established method, as well as its special features and general applicability to different transmission electron microscopes is provided. In addition, the usability of ADT for crystal structure analysis of single nano-sized crystals with and without special crystallographic features, such as twinning, modulations and disorder is demonstrated.

scholarly journals The structure of charoite, (K,Sr,Ba,Mn)15–16(Ca,Na)32[(Si70(O,OH)180)](OH,F)4.0.nH2O, solved by conventional and automated electron diffraction

2010 ◽  
Vol 74 (1) ◽  
pp. 159-177 ◽  
Author(s):  
I. Rozhdestvenskaya ◽  
E. Mugnaioli ◽  
M. Czank ◽  
W. Depmeier ◽  
U. Kolb ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Direct Methods ◽  
Diffraction Tomography ◽  
Chemical Formula ◽  
Crystal Chemical Formula ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Precession Electron Diffraction ◽  
Cation Sites

AbstractCharoite, ideally (K,Sr,Ba,Mn)15–16(Ca,Na)32[(Si70(O,OH)180)](OH,F)4.0·nH2O, a rare mineral from the Murun massif in Yakutiya, Russia, was studied using high-resolution transmission electron microscopy, selected-area electron diffraction, X-ray spectroscopy, precession electron diffraction and the newly developed technique of automated electron-diffraction tomography. The structure of charoite (a = 31.96(6) Å, b = 19.64(4) Å, c = 7.09(1) Å, β = 90.0(1)°, V = 4450(24) Å3, space group P21/m) was solved ab initio by direct methods from 2878 unique observed reflections and refined to R1/wR2 = 0.17/0.21. The structure can be visualized as being composed of three different dreier silicate chains: a double dreier chain, [Si6O17]10–; a tubular loop-branched dreier triple chain, [Si12O30]12–; and a tubular hybrid dreier quadruple chain, [Si17O43]18–. The silicate chains occur between ribbons of edge-sharing Ca and Na-octahedra. The chains of tetrahedra and the ribbons of octahedra extend parallel to the z axis. K+, Ba2+, Sr2+, Mn2+ and H2O molecules lie inside tubes and channels of the structure. On the basis of microprobe analyses and occupancy refinement of the cation sites, the crystal chemical formula of this charoite can be written as (Z = 1): (K13.88Sr1.0Ba0.32Mn0.36)Σ15.56(Ca25.64Na6.36)Σ32 [(Si6O11(O,OH)6)2(Si12O18(O,OH)12)2(Si17O25(O,OH)18)2](OH,F)4.0·3.18H2O.

Dynamical Scattering in Electron Diffraction of wet Protein Crystals

1980 ◽  
Vol 38 ◽  
pp. 42-43
Author(s):  
B. B. Chang ◽  
D. F. Parsons
Keyword(s):  
Electron Diffraction ◽  
Scattering Theory ◽  
Protein Crystals ◽  
Electron Diffraction Data ◽  
Specimen Thickness ◽  
Major Question ◽  
X Ray ◽  
Scattering Effects ◽  
Diffraction Patterns ◽  
Acceleration Voltage

The significance of dynamical scattering effects remains the major question in the structural analysis by electron diffraction of protein crystals preserved in the hydrated state. In the few cases (single layers of purple membrane and 400-600 Å thick catalase crystals examined at 100 kV acceleration voltage) where electron-diffraction patterns were used quantitatively, dynamical scattering effects were considered unimportant on the basis of a comparison with x-ray intensities. The kinematical treatment is usually justified by the thinness of the crystal. A theoretical investigation by Ho et al. using Cowley-Moodie multislice formulation of dynamical scattering theory and cytochrome b5as the test object2 suggests that kinematical analysis of electron diffraction data with 100-keV electrons would not likely be valid for specimen thickness of 300 Å or more. We have chosen to work with electron diffraction patterns obtained from actual wet protein crystals (rat hemoglobin crystals of thickness range 1000 to 2500 Å) at 200 and 1000 kV and to analyze these for dynamical effects.

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