Further Investigation of the Basic Structure of Metastable Mn3Bi by High Resolution Electron Microscopy and Its Computer Simulation

1987 ◽  
Keyword(s):  
Electron Microscopy ◽  
Computer Simulation ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Basic Structure ◽  
Resolution Electron

HIGH RESOLUTION ELECTRON MICROSCOPY OF THE HIGH Tc SUPERCONDUCTOR Bi2Sr2CaCu2O8+δ

1988 ◽  
Vol 02 (06) ◽  
pp. 835-839 ◽  
Author(s):  
M. HERVIEU ◽  
B. DOMENGES ◽  
C. MICHEL ◽  
B. RAVEAU
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction Study ◽  
High Resolution Electron Microscopy ◽  
Basic Structure ◽  
Tetragonal Symmetry ◽  
High Tc ◽  
Resolution Electron ◽  
High Resolution Images ◽  
New Superconductor

The new superconductor Bi 2 Sr 2 CaCu 2 O 8+δ with T c ranging from 80 to 105K, was studied by electron microscopy. The electron diffraction study shows a pseudo-tetragonal symmetry with a≈b≈5.4 Å and c≈30.7 Å and satellites along a, which settle in an incommensurate way. The high resolution images agree with the proposed basic structure. The stacking of the ( BiO y)2 and [ Sr 2 CaCu 2 O 6] layers is quite regular, with only some defects corresponding to c≈24 Å. The lamellar character of the oxide results in splitting and bending of the crystals.

scholarly journals Vitrification of Y zeolite and its effects on HREM images

1986 ◽  
Vol 44 ◽  
pp. 774-775
Author(s):  
R. Csencsits
Keyword(s):  
Electron Microscopy ◽  
Computer Simulation ◽  
Electron Microscope ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Systematic Investigation ◽  
Y Zeolite ◽  
Y Zeolites ◽  
Transmission Electron ◽  
Resolution Electron

High resolution electron microscopy (HREM) is a valuable technique for studying catalytic zeolite systems because it gives direct information about the structure and defects present in the structure. The difficulty with doing an HREM study on zeolites is that they become amorphous under electron irradiation. This work is a systematic investigation of the damage of Y zeolites in the transmission electron microscope (TEM); the goals of this study are to determine the mechanism for electron damage and to access the effects of damage in Y zeolites on their HREM images using computer simulation.

L12- and L10-like cation-ordered structures in ZrO2–Y2O3 ceramics

2001 ◽  
Vol 16 (6) ◽  
pp. 1806-1813 ◽  
Author(s):  
J. C. Rao ◽  
Y. Zhou ◽  
D. X. Li
Keyword(s):  
Electron Microscopy ◽  
Computer Simulation ◽  
High Resolution ◽  
Annealing Temperature ◽  
High Resolution Electron Microscopy ◽  
Energy Dispersive ◽  
Ordered Structures ◽  
X Ray ◽  
Resolution Electron

Y0.25Zr0.75O2−x and Y0.5Zr0.5O2−y phases, with L12- and L10- like cation-ordered structures, respectively, have been found in ZrO2–Y2O3 ceramics in both the sintered and annealed states. High-resolution electron microscopy, energy-dispersive x-ray spectroscopy and computer simulation have been used to reveal the presence of the phases. The formation of Y0.25Zr0.75O2−x and Y0.5Zr0.5O2−y phases was initiated during the sintering procedure and developed with the increase in annealing temperature and time. Segregation of yttrium, which was prevalent in different regions even within one grain, induced the formation of Y0.25Zr0.75O2−x and Y0.5Zr0.5O2−y phases.

High Resolution Electron Microscopy and Computer Simulation Studies of the Atomic Structure of Tilt Boundaries in TiO2

1994 ◽  
Vol 357 ◽  
Author(s):  
Yaping Liu ◽  
Imtiaz Majid ◽  
John B. Vander Sande
Keyword(s):  
Electron Microscopy ◽  
Computer Simulation ◽  
High Resolution ◽  
Atomic Structure ◽  
High Resolution Electron Microscopy ◽  
Resolution Electron ◽  
Symmetric Plane ◽  
Tilt Boundaries ◽  
Computer Simulation Studies ◽  
Simulated Images

AbstractThe atomic structure of [001] tilt grain boundaries of Σ25 (210), Σ5 (310), Σ213 (320) and Σ217 (410) in TiO2 (rutile) were studied using high resolution electron microscopy and computer simulation. Regularly separated small steps (1/2 [120] high) and big steps (3/2 [120] high) which contain secondary dislocations were found in the (210) boundary as a result of deviation from the exact Σ5 misorientation and (210) symmetric plane. Similar steps were also found in (310) and (320) boundaries. Flat segments between the steps were found to have very accurate misorientation of their, Σ's and a nearly symmetric boundary plane. Their rigid body translation, volume expansion and relaxed structures were determined by comparing HRTEM images with computer calculated structures and simulated images. An irregular core structure was found in the (410) boundary when its misorientation deviated 2° from the exact Σ17 misorientation.

Displacement at the twin boundary in YBa2Cu3O7 superconductor

1990 ◽  
Vol 48 (4) ◽  
pp. 18-19
Author(s):  
Yimei Zhu ◽  
M. Pan ◽  
Z.G. Li ◽  
M. Suenaga ◽  
D. Welch
Keyword(s):  
Electron Microscopy ◽  
Computer Simulation ◽  
High Resolution ◽  
Twin Boundary ◽  
High Resolution Electron Microscopy ◽  
Shear Displacement ◽  
Hrem Image ◽  
Twin Structure ◽  
Resolution Electron ◽  
Yba2cu3o7 Superconductor

A shear displacement at the twin boundary in YBa2Cu3O7 superconductor has been observed by means of High Resolution Electron Microscopy. It was found that the a and b planes across the twin boundary are shifted along the boundary by a distance of (1/3 ∼ 1/2) · 2d110. In order to confirm our observation and give an optimum interpretation of the HREM image, computer simulation of the twin structure in YBa2Cu3O7 was carried out.A large supercell, 81.72×21.72×11.70 Å, with a total of 1492 atoms was constructed to simulate the twin structure. The twin boundary is modeled not only by a rotation of the planes in one domain with respect to the adjacent domain by an angle of 90° - ϕ (ϕ≈0.967°) but also by a translation (R= 1/3•2d110) along the boundary. In addition, in order to simulate the diffused boundary, boundary steps in and directions as shown in Fig.1(d) were introduced.

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