Rotation of Image and Selected Area Diffraction Pattern in the RCA‐EMU 3 Electron Microscope

1962 ◽  
Vol 33 (2) ◽  
pp. 246-246 ◽  
Author(s):  
Alfred Baltz
Keyword(s):  
Electron Microscope ◽  
Diffraction Pattern ◽  
Selected Area Diffraction Pattern

Using the TEM Condenser Lens to Switch between Image and Diffraction Modes

2013 ◽  
Vol 21 (2) ◽  
pp. 40-40
Author(s):  
Lydia Rivaud
Keyword(s):  
Electron Microscope ◽  
Diffraction Pattern ◽  
Transmission Electron Microscope ◽  
Condenser Lens ◽  
Selected Area Diffraction Pattern ◽  
Transmission Electron ◽  
Set Up ◽  
Convergent Beam ◽  
Beam Diffraction ◽  
Convergent Beam Diffraction

Central to the operation of the transmission electron microscope (TEM) (when used with crystalline samples) is the ability to go back and forth between an image and a diffraction pattern. Although it is quite simple to go from the image to a convergent-beam diffraction pattern or from an image to a selected-area diffraction pattern (and back), I have found it useful to be able to go between image and diffraction pattern even more quickly. In the method described, once the microscope is set up, it is possible to go from image to diffraction pattern and back by turning just one knob. This makes many operations on the microscope much more convenient. It should be made clear that, in this method, neither the image nor the diffraction pattern is “ideal” (details below), but both are good enough for many necessary procedures.

TEM Observation of the Polytype Transformation of Bulk SiC Ingot

2008 ◽  
Vol 600-603 ◽  
pp. 365-368 ◽  
Author(s):  
Masahiko Aoki ◽  
Megumi Miyazaki ◽  
Taro Nishiguchi ◽  
Hiroyuki Kinoshita ◽  
Masahiro Yoshimoto
Keyword(s):  
Raman Spectroscopy ◽  
Diffraction Pattern ◽  
Growth Direction ◽  
Selected Area Diffraction Pattern ◽  
Polytype Transformation

This article describes the analysis of the polytype transformation of SiC ingot. We analyzed the sample by Raman spectroscopy and TEM observation. The result of the analysis shows the polytype is transformed from 4H-SiC to 6H-SiC, and then returned to 4H-SiC. We found that the direction of the c-axis is not the same as the growth direction of the ingot. And also we found the existence of 8H-SiC at the interface between 6H-SiC and 4H-SiC region by the selected area diffraction pattern and confirmed it by HR-TEM observation.

A metallographic study of the angra dos Reis (iron) meteorite

1971 ◽  
Vol 38 (293) ◽  
pp. 94-101 ◽  
Author(s):  
H. J. Axon ◽  
C. V. Waine
Keyword(s):  
Electron Microscope ◽  
Diffraction Pattern ◽  
Metallic Matrix ◽  
Iron Meteorite ◽  
X Ray Diffraction ◽  
Metallographic Study ◽  
X Ray ◽  
Back Reflection ◽  
Shock Event

SummaryThe Angra dos Reis (iron) has been studied metallographically and an attempt has been made to discuss the circumstances under which the following elements of structure formed: clear etching and frosty etching kamacite, decorated Neumann lines, giant rhabdites, plate rbabdites, rhabdite clusters, microrhabdites, cohenite, and remelted troilite. The remelted troilite is taken to indicate a shock event. However, since there are no metallographically visible indications of shock in the kamacite and since the back reflection X-ray diffraction pattern shows only very faint Debye-Scherrer arcs superimposed on a pattern of sharp spots, it is concluded that the shock event took place at a temperature that allowed shock effects to anneal out of the kamacite almost completely. A submicroscopic precipitate in the metallic matrix is observable with the electron microscope and may represent the final precipitation of phosphide from shocked kamacite.

Electron Image Series Reconstruction of Twin Interfaces in InP Superlattice Nanowires

2011 ◽  
Vol 17 (5) ◽  
pp. 752-758 ◽  
Author(s):  
Martin Ek ◽  
Magnus T. Borgström ◽  
Lisa S. Karlsson ◽  
Crispin J.D. Hetherington ◽  
L. Reine Wallenberg
Keyword(s):  
Electron Microscope ◽  
Diffraction Pattern ◽  
Transmission Electron Microscope ◽  
Interface Structure ◽  
Twin Structure ◽  
Twin Interface ◽  
Transmission Electron ◽  
Electron Image ◽  
Model Structures ◽  
Aberration Corrected

AbstractThe twin interface structure in twinning superlattice InP nanowires with zincblende structure has been investigated using electron exit wavefunction restoration from focal series images recorded on an aberration-corrected transmission electron microscope. By comparing the exit wavefunction phase with simulations from model structures, it was possible to determine the twin structure to be the ortho type with preserved In-P bonding order across the interface. The bending of the thin nanowires away from the intended ⟨110⟩ axis could be estimated locally from the calculated diffraction pattern, and this parameter was successfully taken into account in the simulations.

Image and Diffraction Pattern Rotations in the TEM

2012 ◽  
Vol 20 (5) ◽  
pp. 52-55
Author(s):  
Graham J.C. Carpenter
Keyword(s):  
Electron Microscope ◽  
Diffraction Pattern ◽  
Transmission Electron Microscope ◽  
Image Rotation ◽  
Spiral Path ◽  
Transmission Electron ◽  
Pass Through ◽  
Computer Processor ◽  
Focused Beam ◽  
Imaging Plane

When electrons pass through the electromagnetic lenses in a transmission electron microscope (TEM), they follow a spiral path that results in image rotation. In many TEMs, the image or diffraction pattern that appears at the final imaging plane has therefore suffered a significant rotation compared to the actual specimen. The extent of the rotation is equal to the sum of the contributions from each lens. In some recent instruments an extra lens is built into the column to compensate for these rotations. In the case of a scanning TEM (STEM), where the image is created by scanning a focused beam on the specimen, the orientation of the image to the specimen is fixed but can be controlled electronically by the computer processor.

SmartTilt: The Sensible Way of Tilting

1996 ◽  
Vol 54 ◽  
pp. 452-453 ◽  
Author(s):  
Max T. Otten
Keyword(s):  
Electron Microscope ◽  
Diffraction Pattern ◽  
Mechanical Characteristics ◽  
Crystalline Material ◽  
List Type ◽  
Large Single Crystal ◽  
Specimen Holder ◽  
Transmission Electron ◽  
Semiconductor Specimen ◽  
Experienced Operator

Tilting a crystalline material in the Transmission Electron Microscope to bring it to a particular crystallographic orientation can be an experience that varies from the almost trivial (e.g. in the case of a large single-crystal piece of silicon in a semiconductor specimen) to something that frustrates even the most experienced operator (e.g. in the case of nanometre-sized crystals in a polycrystalline matrix). The problems encountered during such tilting experiments have to do mostly with the following characteristics of the double-tilt holder and goniometer of the microscope:•the second tilt is not eucentric•the mechanical characteristics of the goniometer and specimen holder are such that the forces applied by the tilt drive mechanism can lead to displacements ranging from a few to hundreds of nanometres•the tilt required commonly involves a combination of α and β tilts.Normally the operator has to juggle to keep the crystal within the beam (by applying corrections to the x and/or z goniometer axes), set or adjust the tilt speeds for the α and β tilts, judge how much to tilt with α and β, and assess the result on the diffraction pattern. As a consequence, the whole procedure is normally done in increments, with many intermediate steps, corrections for overshoots, and so on. The time taken to tilt a particular crystal is inversely related to its size. For an experienced operator who knows the relative orientations of the diffraction pattern and the tilt direction, tilting a very small crystal sometimes can take up to tens of minutes. For an inexperienced operator, the procedure commonly results in losing track of the crystal and having to start over with another one.

Sign in / Sign up

Export Citation Format

Share Document