Analysis of high-resolution electron diffraction patterns from purple membrane labelled with heavy-atoms

1990 ◽  
Vol 213 (3) ◽  
pp. 539-560 ◽  
Author(s):  
Thomas A. Ceska ◽  
Richard Henderson
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
Purple Membrane ◽  
Heavy Atoms ◽  
Resolution Electron ◽  
Diffraction Patterns

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.

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.

On the interpretation of electron diffraction patterns from materials containing planar boundaries: the intergrowth tungsten bronzes

1990 ◽  
Vol 429 (1876) ◽  
pp. 91-117 ◽  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
General Interest ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Resolution Imaging ◽  
Diffraction Patterns

Materials containing planar boundaries are of general interest and complete understanding of their structures is important. When direct imaging of the boundaries by, for instance, high-resolution electron microscopy, is impracticable, details of their structure and arrangement may be obtained from electron diffraction patterns. Such patterns are discussed in terms of those from intergrowth tungsten bronzes as specific examples. Fourier-transform calculations for proposed structures have been made to establish, in conjunction with optical-diffraction analogues, the features of the far-field diffraction patterns. These results have been compared with diffraction patterns obtained experimentally by transmission electron microscopy. The aim of the study, to show that the arrangement of the boundaries in these complicated phases can be deduced from their diffraction patterns without the need for high-resolution imaging, has been achieved. The steps to be taken to make these deductions are set out.

Preparation of Frozen Hydrated Purple Membrane for High Resolution Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 72-73
Author(s):  
Jules S. Jaffe ◽  
Robert M. Glaeser
Keyword(s):  
High Resolution ◽  
Structural Information ◽  
Carbon Film ◽  
High Resolution Electron Microscopy ◽  
Purple Membrane ◽  
Current Time ◽  
Cold Stage ◽  
Resolution Electron ◽  
Diffraction Patterns ◽  
Transfer Device

At the current time the only method that has led to high resolution structural information greater than 7 Å has been the glucose embedment method of Unwin and Henderson. We have recently been successful in obtaining high resolution electron diffraction patterns of purple membrane (PM) in ice. Routine preparation of membranes was facilitated by the use of a double carbon film technique which permitted controlled evaporation of the solution. Rapid freezing was accomplished by immediately submerging these preparations into LN2 - Specimens prepared in this way were inserted into a JEOL 100-B microscope using a cryo-transfer device and observed at temperatures of -130°C using a LN2 cold stage.

Application of the imaging plate to quantitative analysis of electron-diffraction and high-resolution electron microscopy

1989 ◽  
Vol 47 ◽  
pp. 666-667
Author(s):  
K. Hiraga ◽  
D. Shindo ◽  
M. Hirabayashi ◽  
T. Oikawa ◽  
N. Mori ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Quantitative Analysis ◽  
High Resolution ◽  
Electron Diffraction ◽  
Electron Micrographs ◽  
High Resolution Electron Microscopy ◽  
Imaging Plate ◽  
Resolution Electron ◽  
Diffraction Patterns ◽  
High Resolution Electron Micrographs

The “Imaging Plate” (IP) has three superior characteristics, i.e., high sensitivity to the electron beam, and a wide dynamic range and good linearity for electron dose compared with conventional EM films. The use of the IP is expected to lead to quantitative analysis of electron microscopy. The purpose of the present work is to examine the possibility of application of the IP to the quantitative analysis of electron diffraction and high-resolution electron microscopy.By using the TEM-IP System developed by Oikawa et al., which is published in this conference, electron diffraction patterns and high-resolution electron micrographs taken on the IP with an effective size of 102 х 77 mm2 were convertedinto digital data of 2048 х 1536 pixels with 4096 gray levels. Observations of electron diffraction patterns and high-resolution electron micrographs were made with a 200 kV (JEM-2000FX) and a 400 kV (JEM-4000EX) electron microscope, respectively.

Electron Microscopy of Frozen, Hydrated Biological Specimens

1975 ◽  
Vol 33 ◽  
pp. 300-301
Author(s):  
Kenneth A. Taylor
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Liquid Nitrogen ◽  
Electron Irradiation ◽  
Biological Material ◽  
Biological Materials ◽  
Composite Support ◽  
Resolution Electron ◽  
Diffraction Patterns

Recently, a method has been developed in this laboratory for maintaining the hydration of biological materials by using frozen specimens. With this technique specimens are prepared using folding grids on which are mounted composite support films of carbon and SiO. The technique essentially embeds the biological material in a thin aqueous film between the two supporting films. The sandwiched specimens are then frozen directly in liquid nitrogen. While it was thought at first that freezing directly in liquid nitrogen might cause disordering of periodic or crystalline biological specimens, this has been shown not to be the case. High resolution electron diffraction patterns have been obtained from frozen unstained catalase crystals.The microscopy of frozen specimens depends on their resistance to damage by electron irradiation. The critical exposure for fading of the electron diffraction intensities from frozen unstained catalase crystals has been measured.

Plan-view microstructures of Co/Ru bilayers

1995 ◽  
Vol 10 (6) ◽  
pp. 1539-1545 ◽  
Author(s):  
G.Z. Pan ◽  
A. Michel ◽  
V. Pierron-Bohnes ◽  
P. Vennéguès ◽  
M.C. Cadeville
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
High Resolution Electron Microscopy ◽  
Image Contrast ◽  
Misfit Dislocations ◽  
Double Diffraction ◽  
Plan View ◽  
Resolution Electron ◽  
Diffraction Patterns

Plan-view microstructures of two Co/Ru bilayers with a composition of [Co12ÅRu45Å]2 and [Co40ÅRu35Å]2 have been studied by conventional and high resolution electron microscopy. Large differences in electron diffraction and image contrast between the two bilayers were observed, which are recognized as the microstructural variations during the relaxation of large coherent planar strains when the Co layers wet coherently or semicoherently the Ru layers. For the [Co12ÅRu45Å]2 bilayer, the Co layers are unrelaxed from the Ru layers; only one set of electron diffraction patterns was observed, and the image consists of three types of contrasts which are closely related with either the generation and movement of misfit dislocations or large coherent strains. For the [Co40ÅRu35Å]2 bilayer, the Co layers are relaxed basically from the Ru layers; two sets of electron diffraction patterns with double diffraction spots were observed, and the image consists of small irregular areas with moiré fringe dots.

Modulated Structure of Bi1.8Sr2.0Rh1.6Ox

2007 ◽  
Vol 336-338 ◽  
pp. 818-821
Author(s):  
Kunio Yubuta ◽  
Satoshi Okada ◽  
Yuzuru Miyazaki ◽  
Ichiro Terasaki ◽  
Tsuyoshi Kajitani
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
High Resolution Electron Microscopy ◽  
Layered Crystal ◽  
Structural Analogue ◽  
Modulated Structure ◽  
Incident Electron Beam ◽  
Resolution Electron ◽  
High Resolution Images ◽  
Diffraction Patterns

We have investigated the modulated structure of the misfit-layered crystal Bi1.8Sr2.0Rh1.6Ox by means of electron diffraction and high-resolution electron microscopy. This compound consists of two interpenetrating subsystems of a hexagonal RhO2 sheet and a distorted four-layered rock-salt-type (Bi,Sr)O block. Both subsystems have common a-, c-axes and β-angles with a = 5.28 Å, c = 29.77 Å and β = 93.7º. On the other hand, the crystal structure is incommensurated parallel to the b-axes, among which b1 = 3.07 Å for the RhO2 sheet and b2 = 4.88 Å for the (Bi,Sr)O block. The misfit ratio, b1/b2 ~ 0.63, characterizes the structural analogue as [Bi1.79Sr1.98Oy]0.63[RhO2]. This compound has two modulation vectors, i.e., q1 = – a* + 0.63b1* and q2 = 0.17b1* + c*, and the superspace group is assigned as the Cc(1β0, 0μ1)-type from the electron diffraction patterns. High-resolution images taken with the incident electron beam parallel to the a- and c-axes clearly show displacive as well as compositional modulations.

High Resolution Electron Microscopy and Electron Diffraction of YBa2Cu3O7−x

1987 ◽  
Vol 99 ◽  
Author(s):  
William Krakow ◽  
Thomas M. Shaw
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
Oxygen Vacancies ◽  
Computer Experiments ◽  
High Resolution Electron Microscopy ◽  
Simulation Experiments ◽  
Resolution Electron ◽  
Short Range Ordering ◽  
Diffraction Patterns ◽  
High Resolution Electron Micrographs

ABSTRACTExperimental high resolution electron micrographs and computer simulation experiments have been used to evaluate the visibility of the atomic constituents of YBa2Cu3O7−x. In practice, the detection of oxygen has not been possible in contradiction to that predicted by modelling of perfect crystalline material. Preliminary computer experiments of the electron diffraction patterns when oxygen vacancies are introduced on the Cu-O sheets separating Ba layers show the diffuse streaks characteristic of short range ordering.

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