Computation of electron‐diffraction patterns in Lorentz electron microscopy of thin magnetic films (abstract)

1991 ◽  
Vol 69 (8) ◽  
pp. 5890-5890 ◽  
Author(s):  
M. Mansuripur
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Magnetic Films ◽  
Thin Magnetic Films ◽  
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.

A study of the high-Cu Al–Cu–Co decagonal phase

1993 ◽  
Vol 8 (7) ◽  
pp. 1473-1476 ◽  
Author(s):  
B. Grushko
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Diffraction ◽  
Diffuse Scattering ◽  
Nonequilibrium State ◽  
Zone Axis ◽  
Decagonal Phase ◽  
Diffraction Patterns ◽  
Scanning Electron

The decagonal phase was studied by transmission and scanning electron microscopy in an Al62Cu24Co14 alloy annealed at 550–850 °C. The electron diffraction patterns of the decagonal phase exhibited weak quasiperiodic odd-n reflections in the [1-2100] zone axis corresponding to the equilibrated structure. The relative intensities of these reflections were significantly lower in the Al62Cu24Co14 than in the Al68Cu11Co21 decagonal phase. Diffuse scattering observed previously at the same positions can be related to a nonequilibrium state of the decagonal phase.

Atomic structure of YB56 studied by digital high-resolution electron microscopy and electron diffraction

2001 ◽  
Vol 16 (1) ◽  
pp. 101-107 ◽  
Author(s):  
Takeo Oku ◽  
Jan-Olov Bovin ◽  
Iwami Higashi ◽  
Takaho Tanaka ◽  
Yoshio Ishizawa
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
High Resolution Electron Microscopy ◽  
Charge Coupled Device ◽  
X Ray ◽  
Resolution Electron ◽  
High Resolution Images ◽  
Diffraction Patterns ◽  
Simulated Images

Atomic positions for Y atoms were determined by using high-resolution electron microscopy and electron diffraction. A slow-scan charge-coupled device camera which had high linearity and electron sensitivity was used to record high-resolution images and electron diffraction patterns digitally. Crystallographic image processing was applied for image analysis, which provided more accurate, averaged Y atom positions. In addition, atomic disordering positions in YB56 were detected from the differential images between observed and simulated images based on x-ray data, which were B24 clusters around the Y-holes. The present work indicates that the structure analysis combined with digital high-resolution electron microscopy, electron diffraction, and differential images is useful for the evaluation of atomic positions and disordering in the boron-based crystals.

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.

Domains in Thin Magnetic Films Observed by Electron Microscopy

1960 ◽  
Vol 31 (10) ◽  
pp. 1699-1705 ◽  
Author(s):  
Harrison W. Fuller ◽  
Murray E. Hale
Keyword(s):  
Electron Microscopy ◽  
Magnetic Films ◽  
Thin Magnetic Films

Compositional variation within some sedimentary chlorites and some comments on their origin

1985 ◽  
Vol 49 (352) ◽  
pp. 375-386 ◽  
Author(s):  
C. D. Curtis ◽  
C. R. Hughes ◽  
J. A. Whiteman ◽  
C. K. Whittle
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Compositional Variation ◽  
Analytical Transmission Electron Microscopy ◽  
Decomposition Reactions ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Crystal Electron

AbstractA range of authigenic sedimentary chlorites from sandstones has been studied by analytical transmission electron microscopy. Selected area (single crystal) electron diffraction patterns are of the Ib (β = 90°) polytype confirming the earlier observations of Hayes (1970).TEM analyses show all samples to be relatively rich in both Al and Fe. In the general formula (Mg,Fe,Al)n [Si8−xAlxO20](OH)16, x varies between 1.5 and 2.6; Fe/(Fe + Mg) between 0.47 and 0.83 and n between 10.80 and 11.54. Octahedral Al is close to 3 in this formulation and Fe2+ predominates over Fe3+. Swelling chlorites have significantly different compositions which are consistent with smectite/chlorite interstratifications.The Ib (β = 90°) polytype appears to be stable under conditions of moderate to deep burial. It replaces berthierine and swelling chlorites formed at lower temperatures. As commonly seen in grain coatings, however, it precipitates from porewater; solutes probably being contributed from several mineral decomposition reactions.

Electron diffraction of helical structures

1992 ◽  
Vol 50 (1) ◽  
pp. 518-519
Author(s):  
T. Ruiz ◽  
R. Diaz ◽  
J-L. Ranck ◽  
D.L.D. Caspar ◽  
D.J. DeRosier
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Helical Structure ◽  
Lipid Monolayer ◽  
Electron Diffraction Data ◽  
Helical Structures ◽  
Protein Aggregate ◽  
X Ray ◽  
Isomorphous Replacement ◽  
Diffraction Patterns

Electron microscopy has advantages over X-ray diffraction for the study of helical structures. For X-ray studies, one needs large well oriented samples which are difficult to obtain. Only one helical structure, TMV, has been solved by conventional X-ray analysis using multiple isomorphous replacement. In contrast, one requires single particles or small rafts for studies by electron microscopy. We are attempting to use a combination of imaging and electron diffraction data to analyze helical structures at 9-10 Å resolution in order to visualize α-helices. To obtain electron diffraction patterns we produced well-ordered domains (∽ 1-3 μm in diameter) for diffraction work. Several methods succeeded in aligning helical particles : the lipid monolayer technique, mica sandwiching and unidirectional blotting. The lipid monolayer technique proved to be the best for high resolution work. The three samples under study (flagellar filaments from Salmonella typhimurium, TMV and TMV stacked disk protein aggregate) gave electron diffraction patterns out to ∽10 Å resolution.

Small-Spot Illumination For High-Resolution Electron Microscopy of Beam-Sensitive Specimens

1985 ◽  
Vol 43 ◽  
pp. 320-321
Author(s):  
Kenneth H. Downing ◽  
Robert M. Glaeser
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
High Resolution ◽  
Electron Diffraction ◽  
High Resolution Electron Microscopy ◽  
Photographic Emulsion ◽  
Lateral Motion ◽  
Small Spot ◽  
Resolution Electron ◽  
Diffraction Patterns

The contrast observed in images of beam-sensitive, crystalline specimens is found to be significantly less than one would predict based on observations of electron diffraction patterns of the specimens. Factors such as finite coherence, inelastic scattering, and the limited MTF of the photographic emulsion account for some decrease in contrast. It appears, however, that most of the loss in signal is caused by motion of the specimen during exposure to the electron beam. The introduction of point and other defects in the crystal, resulting from radiation damage, causes bending and lateral motion, which degrade the contrast in the image. We have therefore sought to determine whether the beam-induced specimen motion can be reduced by reducing the area of the specimen which is illuminated at any one time.

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