scholarly journals Symposium on Ultrafast Electron Microscopy and Ultrafast Science

2009 ◽  
Vol 15 (4) ◽  
pp. 271-271 ◽  
Author(s):  
Mitra L. Taheri ◽  
Nigel D. Browning ◽  
John Lewellen
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Materials Science ◽  
Dynamic Characterization ◽  
X Ray Diffraction ◽  
Ultrafast Electron Diffraction ◽  
X Ray ◽  
Ultrafast Science ◽  
Wide Range ◽  
Technological Opportunities

Dynamic characterization techniques have been utilized in the fields of biology, chemistry, physics, and materials science for many years. Techniques range from neutron scattering to X-ray diffraction. Two of the fields experiencing much development recently have been electron-based techniques. Namely, ultrafast electron diffraction (UED) and ultrafast electron microscopy (UEM) have been advancing rapidly, but unfortunately, in parallel. We are approaching an era where the convergence of these two techniques could open up a wide range of scientific and technological opportunities and advancements.

Synthesis of Fe2O3/CNTs for the Fast Removal of Tetracycline from Aqueous Solutions

2014 ◽  
Vol 915-916 ◽  
pp. 933-941 ◽  
Author(s):  
Zhong Jie Zhang ◽  
Chang Yu Lu ◽  
Wei Huang ◽  
Wei Sheng Guan ◽  
Yue Xin Peng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Magnetic Measurements ◽  
Ferrite Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Wide Range ◽  
Fast Removal ◽  
Scanning Electron

The effective remove to tetracycline still remains a big challenge for scientists. In this work, we used a new method for preparing functional magnetic CNTS with ferrite nanoparticles. A wide range of techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and magnetic measurements were applied to characterize the obtained Fe2O3/CNTs. Moreover, we have also studied the properties of adsorbent to tetracycline. In addition, we have found that the Fe2O3/CNTs are better reusable adsorbent than other traditional adsorbents by magnetic separation recycling method.

Halloysite in some soils from north-east Scotland

Clay Minerals ◽  
1977 ◽  
Vol 12 (1) ◽  
pp. 59-66 ◽  
Author(s):  
M. J. Wilson ◽  
J. M. Tait
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Soil Samples ◽  
X Ray Diffraction ◽  
X Ray ◽  
Drainage Class ◽  
North East ◽  
Parent Rocks ◽  
Diffraction Patterns

AbstractX-ray diffraction and electron microscopy show that halloysite occurs widely in soils derived from a variety of parent rocks (granite, gabbro, schist and slate) in north-east Scotland. Both tubular and non-tubular forms are observed, the latter being characterized by electron diffraction patterns with 001 reflection either absent or very weak and diffuse. Clay fractions from a poorly drained profile separated without prior drying of the soil samples contain essentially dehydrated halloysite at the surface, this becoming progressively more hydrated with depth. Since halloysite occurs extensively in soils of widely varying drainage class the mineral is probably not the result of recent soilforming processes but may have originated during Tertiary or interglacial weathering.

An Electron Microscopy study of the BaxLa1-xFeO3-x/2 (1/2≤x≤2/3) system

1990 ◽  
Vol 48 (4) ◽  
pp. 608-609
Author(s):  
M. Parras ◽  
J.M. González-Calbet ◽  
M. Vallet-Regí ◽  
J.C. Grenier
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Chemical Analysis ◽  
Analysis Data ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compositional Variations ◽  
Perovskite Unit Cell

In a previous paper we have shown that compositional variations in BaxLa1-xFeO3-y materials prepared in air. are accommodated in a different way than in other perovskite-related ferrites probably due to the bigger size of barium.When oxidated BaxLa1-xFe3+,4+O3-y samples in the 1/2 ≤ x ≤ 2/3 range, are reduced by annealing at 1100°C for 24h. in flowing Ar-5%H2, all iron,as deduced from chemical analysis data, is found in the III state oxidation. Powder X-ray diffraction data in this range (La1/2Ba1/2FeO2.75-La1/3Ba2/3FeO2.67) can be indexed on the basis of a single cubic perovskite unit cell (ac ≃ 3.95Å)In order to elucidate the way in which anionic vacancies are accommodated in these solids an electron diffraction (ED) and microscopy study was performed, similar results being obtained in both La1/2Ba1/2 FeO2.75 and La1/3Ba2/3FeO2.67samples.

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.

Electron-diffraction study of subsidiary maxima of scattered intensity in nepheline

1962 ◽  
Vol 33 (257) ◽  
pp. 114-124 ◽  
Author(s):  
J. D. C. McConnell
Keyword(s):  
Thermal Treatment ◽  
Electron Diffraction ◽  
Diffraction Study ◽  
Electron Diffraction Study ◽  
Scattered Intensity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Subsidiary Maxima ◽  
Similar Intensity

SummaryA detailed electron and X-ray diffraction study of a suite of nephelines from a wide range of paragenetic environments indicates that, in all cases studied, additional weak maxima of scattered intensity are present. Similar intensity maxima have previously been observed and described in an isolated case by Sahama. Thermal treatment at temperatures as low as 200° C causes these maxima to become noticeably diffuse, implying a structural transformation.

Microcavity Effects in The Luminescence of GaAs Microcrystals

1992 ◽  
Vol 283 ◽  
Author(s):  
S. Juen ◽  
K. F. Lamprecht ◽  
R. Rodrigues ◽  
R. A. Höpfel
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Three Dimensional ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
Bulk Gaas ◽  
X Ray ◽  
Transmission Electron ◽  
Spectral Enhancement

ABSTRACTExperimental photoluminescence spectra of GaAs microcrystals show pronounced variations compared to the luminescence of bulk GaAs. The observed spectra are explained by spectral enhancement and inhibition of spontaneous emission in a three-dimensional optical resonator formed by a dielectrically confined semiconductor microcrystal. The crystals were produced by pulverization of bulk GaAs, size-separated by sedimentation techniques, and characterized by transmission electron microscopy, electron diffraction and x-ray diffraction.

Synthesis Of Highly Ordered Macroporous Minerals: Extension of the Synthetic Method to Other Metal Oxides and Organic-Inorganic Composites

1998 ◽  
Vol 549 ◽  
Author(s):  
C.F. Blanford ◽  
T.N. Do ◽  
B.T. Holland ◽  
A. Stein
Keyword(s):  
Electron Microscopy ◽  
Metal Oxides ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Wide Range ◽  
Ordered Macroporous ◽  
Lower Temperature

AbstractThe facile synthesis of three-dimensional macroporous arrays of titania, zirconia and alumina was recently reported [1]. The synthesis of these materials has now been extended to the oxides of iron, tungsten, and antimony, as well as a mixed yttrium-zirconium system and organically modi- fied silicates. These materials were characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray energy dispersive spectrometry (EDS), and powder X-ray diffraction (XRD). Ordered structures of iron, tungsten, and antimony were formed from alkoxide precursors as in the originally reported synthesis, but the template was removed at a lower temperature. Samples of vinyl- and 2-cyanoethyl-modified silicates were formed from a mixture of organotrialkoxysilane and tetraalkoxysilane precursors; the polystyrene template was removed by extraction with a THF/acetone mixture. These results show the ease of extending the original syn- thesis to a wide range of systems. Also, the ability to form homogenous mixed-metal oxides will be important for tailoring the dielectric and photonic properties of these materials.

Structure determination of a new polymorph of TiO2 by high-resolution electron microscopy and computer simulations

1989 ◽  
Vol 47 ◽  
pp. 416-417
Author(s):  
Jillian F. Banfield ◽  
David R. Veblen ◽  
David J. Smith
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Computer Simulations ◽  
High Resolution Electron Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naturally Occurring ◽  
Resolution Electron

A new, naturally occurring polymorph of TiO2 has been identified. This mineral forms lamellae generally only a few nanometers wide in anatase from two localities near Bintal Valais, Switzerland. The abundance of this mineral in anatase is too low to allow investigation by X-ray diffraction. The unit cell determined by electron diffraction is triclinic, with a = 0.754 nm, b = 0.448 nm, c = 0.616 nm, α = 78.90°, β = 124.55°, γ = 96.54°. The coherently intergrown lamellae are oriented with b parallel to a of anatase; the interface is parallel to (103) anatase.

Complex Superstructures Resulting from Compositional Modulation and Octahedral Tilt Twinning in AA′BB′O6 Doubly Cation Ordered Perovskites

2013 ◽  
Vol 2013 (CICMT) ◽  
pp. 000006-000013
Author(s):  
Graham King ◽  
Susana Garcia-Martin ◽  
Esteban Urones-Garrote ◽  
Gwilherm Nenert ◽  
Patrick M. Woodward
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Neutron Powder Diffraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compositional Modulation ◽  
System A ◽  
Transmission Electron

The ordering of cations within the perovskite structure can have a profound effect on the physical properties. A number of AA′BB′O6 perovskite phases which have both a rock salt ordering of the B/B′ cations and a layered ordering of the A/A′ cations have recently been prepared and studied. In some of these compositions complex nanoscale superstructure formation has been observed. These superstructures are the result of compositional modulations involving the occupancies of the A and A′ cations and are accompanied by a twinning of the octahedral tilt system. A wide variety of patterns are observed, such as 1-dimensional stripes or 2-dimensional chessboards which can have periodicities which are either commensurate or incommensurate with the underlying subcell. These superstructures cannot be easily detected by powder X-ray diffraction but have been observed using a combination of high resolution transmission electron microscopy, electron diffraction, and neutron powder diffraction. The factors which determine the dimensionality and periodicity of the superstructures are discussed and compared with the closely related Li based perovskite systems.

scholarly journals Effect of Growth Temperature and Time on Morphology and Gas Sensitivity of Cu2O/Cu Microstructures

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Ling Wu ◽  
Lun Zhang ◽  
Zhipeng Xun ◽  
Guili Yu ◽  
Liwei Shi
Keyword(s):  
Electron Microscopy ◽  
Gas Sensors ◽  
Gas Sensing ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
X Ray ◽  
Transmission Electron ◽  
Wide Range ◽  
Gas Response

A facile hydrothermal synthesis with CuSO4as the copper source was used to prepare micro/nano-Cu2O. The obtained samples have been characterized by X-ray diffraction, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). With increasing the reaction temperature and time, the final products were successively Cu2O octahedron microcrystals, Cu2O/Cu composite particles, and a wide range of Cu spherical particles. The gas sensitivity of products towards ethanol and acetone gases was studied. The results showed that sensors prepared with Cu2O/Cu composites synthesized at 65°C for 15 min exhibited optimal gas sensitivity. The gas sensing mechanism and the effect of Cu in the enhanced gas response were also elaborated. The excellent gas sensitivity indicates that Cu2O/Cu composites have potential application as gas sensors.

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