Utilization of Selected Area Electron Diffraction Patterns for Characterization of Air Submicron Particulate Matter Collected by a Thermophoretic Precipitator

2003 ◽  
Vol 53 (2) ◽  
pp. 227-236 ◽  
Author(s):  
John J. Bang ◽  
Elizabeth A. Trillo ◽  
Lawrence E. Murr
Keyword(s):  
Particulate Matter ◽  
Electron Diffraction ◽  
Selected Area Electron Diffraction ◽  
Diffraction Patterns

scholarly journals Nano-Scale Rare Earth Distribution in Fly Ash Derived from the Combustion of the Fire Clay Coal, Kentucky

Minerals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 206 ◽  
Author(s):  
James Hower ◽  
Dali Qian ◽  
Nicolas Briot ◽  
Eduardo Santillan-Jimenez ◽  
Madison Hood ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Fly Ash ◽  
Electron Diffraction ◽  
Eastern Kentucky ◽  
Nano Scale ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Fire Clay

Fly ash from the combustion of eastern Kentucky Fire Clay coal in a southeastern United States pulverized-coal power plant was studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). TEM combined with elemental analysis via energy dispersive X-ray spectroscopy (EDS) showed that rare earth elements (REE; specifically, La, Ce, Nd, Pr, and Sm) were distributed within glassy particles. In certain cases, the REE were accompanied by phosphorous, suggesting a monazite or similar mineral form. However, the electron diffraction patterns of apparent phosphate minerals were not definitive, and P-lean regions of the glass consisted of amorphous phases. Therefore, the distribution of the REE in the fly ash seemed to be in the form of TEM-visible nano-scale crystalline minerals, with additional distributions corresponding to overlapping ultra-fine minerals and even true atomic dispersion within the fly ash glass.

Electron diffraction from crystal defects: Fraunhofer effects from plane faults

1966 ◽  
Vol 293 (1433) ◽  
pp. 169-180 ◽  
Keyword(s):  
Electron Diffraction ◽  
Intensity Distribution ◽  
Stacking Faults ◽  
Dynamical Theory ◽  
Crystal Defects ◽  
Similar Calculation ◽  
Selected Area Electron Diffraction ◽  
Periodic Intensity ◽  
Diffraction Patterns ◽  
Calculated Intensity

The selected area electron diffraction patterns from a crystal containing a stacking fault have been observed to exhibit a number of unusual features. In some cases a periodic intensity distribution about the Bragg spot, in other cases streaking. By applying Kirchhoff’s theory of diffraction and using the dynamical theory of electron diffraction this intensity distribution around the Bragg spots in the electron diffraction patterns from stacking faults has been calculated. The calculated intensity distributions compare favourably with experiment. A similar calculation has also been carried out to predict the intensity distribution around Bragg spots in the selected area electron diffraction patterns from a crystal containing a grain boundary.

Electron Diffraction Study of Multilayer Structures with Partially Coherent Illumination

1985 ◽  
Vol 62 ◽  
Author(s):  
N. Otsuka ◽  
C. Choi ◽  
L. A. Kolodziejski ◽  
R. L. Gunshor
Keyword(s):  
Electron Diffraction ◽  
Incident Beam ◽  
Electron Diffraction Study ◽  
Diffraction Theory ◽  
Diffraction Spot ◽  
Multilayer Structures ◽  
Intensity Calculations ◽  
Diffraction Patterns ◽  
Monochromatic Source

ABSTRACTThe effect of partial coherency on electron diffraction patterns of Cd1−xMnxTe – Cd1−yMny Te superlattices has been investigated. Observed diffraction patterns are compared with intensity calculations performed using dynamical diffraction theory with a model of an extended incoherent monochromatic source. From this study, a new method of electron diffraction for characterization of multilayer structures can be developed. Under the condition that the lateral coherent distance of the incident beam covers two adjacent layers, diffraction beams arising from the two layers give rise to an interference fringe in a diffraction spot. With this type of diffraction pattern, one can determine the refractive index of a crystal in the multilayer structure.

Synthesis and Characterization of Srilankite Nanowires

2008 ◽  
Vol 8 (3) ◽  
pp. 1481-1488 ◽  
Author(s):  
Marguerite Germain ◽  
Philip Fraundorf ◽  
Sam Lin ◽  
Elena A. Guliants ◽  
Christopher E. Bunker ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Superlattice Structure ◽  
Titanate Nanowires ◽  
Alkaline Conditions ◽  
Diffraction Patterns

We describe the synthesis and characterization of srilankite (Ti2ZrO6) nanowires. The nanowires are produced via hydrothermal synthesis with a TiO2/ZrO2 mixture under alkaline conditions. The zirconium titanate nanowires have median diameters of 60 nm and median lengths of 800 nm with the 〈022〉 axis along the length of the nanowire. Electron microscopy, energy dispersive X-ray spectroscopy, powder X-ray diffraction, and electron diffraction are used to characterize the phases and compare nanowires produced with varying molar ratios of Ti and Zr. Electron diffraction patterns produced from single nanowires show highly crystalline nanowires displaying a compositional-ordering superlattice structure with Zr concentrated in bands within the crystal structure. This is in contrast to naturally occurring bulk srilankite where Zr and Ti are randomly substituted within the crystal lattice. Streaking is observed in the electron diffraction patterns suggesting short-range ordering within the superlattice structure.

Selected Area Electron Diffraction and its Use in Structure Determination

2010 ◽  
Vol 18 (4) ◽  
pp. 22-28
Author(s):  
William F. Tivol
Keyword(s):  
Structural Analysis ◽  
Electron Diffraction ◽  
Structure Determination ◽  
Limited Region ◽  
Selected Area Electron Diffraction ◽  
Electron Microscopes ◽  
Diffraction Patterns ◽  
Technical Considerations

One of the capabilities of electron microscopes is to obtain diffraction patterns, which can be analyzed to give information about the structure of the specimen. This brief review discusses some of the technical considerations in using electron diffraction patterns for structural analysis. The technique of selected-area electron diffraction uses diffraction obtained from a limited region of the specimen.

Fine Structure in the Selected Area Electron Diffraction Patterns of Beidellite

1975 ◽  
Vol 33 ◽  
pp. 72-73
Author(s):  
N. Güven ◽  
R.W. Pease
Keyword(s):  
Fine Structure ◽  
Electron Diffraction ◽  
Reciprocal Lattice ◽  
Linear Chain ◽  
Lattice Points ◽  
Selected Area Electron Diffraction ◽  
General Terms ◽  
Regular Network ◽  
Diffraction Patterns ◽  
Pass Through

Selected area electron diffraction (SAD) patterns of beidellite exhibit fine structure in the form of nonradial streaks and extra spots between the normal Laue spots. The streaks form a regular network as shown in Figure 1A andvery clearly after a long exposure, in Fig. IB. These streaks do not pass through the origin and they are not symmetrical with respect to the reciprocal lattice points. Therefore they cannot be caused by finite crystallite size. The distribution of the streaks suggests a strong anisotropy in the beidellite structure as they are restricted to the directions parallel to [11], [11], and [02]. However, there are no streaks along the actual [11], [11] and [02] directions. In general terms, these linear streaks are explained by the presence of ‘continuous sheets’ or ‘walls’ of intensity in reciprocal space. These intensity 'walls' are associated with a linear chain of scatterers in the crystal in the direction perpendicular to the intensity sheets. Such linear scatterers may be produced by small shifts of certain atoms due to thermal motion, isomorphic substitutions, distortions, or other lattice imperfections.

A “filmless” method of acquiring and measuring electron diffraction patterns

1996 ◽  
Vol 54 ◽  
pp. 594-595 ◽  
Author(s):  
D. C. Dufner
Keyword(s):  
Electron Diffraction ◽  
User Interaction ◽  
Computer Programs ◽  
Specific Aspect ◽  
Convenient Means ◽  
Standard Procedures ◽  
Measurement And Analysis ◽  
Diffraction Patterns

Electron diffraction is one of most widely used techniques in the characterization of specimens in the TEM. With the advent of computerization, there is a growing trend toward automation of the measurement and analysis of electron diffraction patterns (EDPs). There are a number of computer programs used for measuring, indexing, and simulating EDPs, some of which are now commercially available. Many of these programs are stand-alone programs which either perform a specific aspect of EDP analysis or require significant user interaction, particularly in the measurement phase. In some cases, the lack of suitable algorithms for measuring EDPs usually limit these programs to the extent that users still have to perform standard procedures of measuring EDPs from negatives or prints to obtain the necessary values needed to complete the execution of these programs. Here, a more convenient means for online acquisition and measurement of EDPs is presented.

Automatic Computer Measurement of Selected Area Electron Diffraction Patterns from Asbestos Minerals

1988 ◽  
Vol 32 ◽  
pp. 593-600
Author(s):  
J. C. Russ ◽  
T. Taguchi ◽  
P. M. Peters ◽  
E. Chatfield ◽  
J. C. Russ ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Diffraction Data ◽  
Automatic Method ◽  
Automatic Computer ◽  
Selected Area Electron Diffraction ◽  
Computer Measurement ◽  
Integrated Intensity ◽  
Diffraction Patterns ◽  
True Center

Conventional selected area diffraction patterns as obtained in the TEM present difficulties for identification of materials such as asbestifonn minerals, although diffraction data is considered to be one of the preferred methods for making this identification. The preferred orientation of the fibers in each field of measurement, and the spotty patterns that are obtained, do not readily lend themselves to measurement of the integrated intensity values for each dspacing, and even the d-spacings may be hard to determine precisely because the true center location for the broken rings requires estimation. To overcome these problems, we have implemented an automatic method for diffraction pattern measurement. It automatically locates the center of patterns with high precision, measures the radius of each ring of spots in the pattern, and integrates the density of spots in that ring.

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