Development of an automatic electron diffraction pattern analyzing system

1983 ◽  
Vol 41 ◽  
pp. 400-401
Author(s):  
S. Moriguchi ◽  
T. Shinkawa ◽  
E. Watanabe ◽  
Y. Makita ◽  
S. Sakurai ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Electron Diffraction Pattern ◽  
Incident Beam ◽  
Light Level ◽  
Lattice Constants ◽  
Video Signals ◽  
Hardware System ◽  
Transmission Electron

The electron diffraction pattern has information on the crystal structure of samples, such as the crystal system, lattice constants and the orientation for the incident beam. Material can be identified by measuring the above characteristics and, in general principle by measuring their accurate lattice spacings. However, this measurement requires a lot of time and fundamental knowledge of the crystal structure.The present automatic analyzing system of the electron diffraction pattern makes the analysis ease. The outline of this system is described in this paper.The hardware system consists roughly of three components; a low-light-level TV device called the image carrier, a frame memory, and a minicomputer. The image carrier transforms the image formed on the flourescent screen of a transmission electron microscope (TEM) into video signals. The frame memory is provided with a memory plane of 512 x 512 pixels, each having 256 gray levels. It digitaizes video signals of the image and stores them in itself.

In-Situ Transmission Electron Microscopy Investigation of Aluminum Induced Crystallization of Amorphous Silicon

2008 ◽  
Vol 1066 ◽  
Author(s):  
Ram Kishore ◽  
Renu Sharma ◽  
Satoshi Hata ◽  
Noriyuki Kuwano ◽  
Yoshitsuga Tomokiyo ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Amorphous Silicon ◽  
Diffraction Pattern ◽  
Electron Diffraction Pattern ◽  
Polycrystalline Silicon ◽  
Nanocrystalline Silicon ◽  
Transmission Electron ◽  
In Situ Heating ◽  
Induced Crystallization

ABSTRACTThe interaction of amorphous silicon and aluminum films to achieve polycrystalline silicon has been investigated using transmission electron microscope equipped with in-situ heating holder. Carbon coated nickel grids were used for TEM studies. An ultra high vacuum cluster tool was used for the deposition of a ∼50nm a-Si films and a vacuum deposition system was used to deposit a ∼50nm Al films on a-Si film. The microstructural features and electron diffraction in the plain view mode were observed with increase in temperature starting from room temperature to 275 °C. The specimen was loaded inside TEM heating holder. The temperature was measured and kept constant for 5 minutes during which the microstructure at fixed magnification of X63K was recorded and the electron diffraction pattern of the same area was also recorded. The temperature was then increase and fixed at desired value and microstructure and EDP were again recorded. The temperatures used in this experiment were 30, 100, 150, 200, 225, 275°C. A sequential change in microstructural features and electron diffraction pattern due to interfacial diffusion of boundary between Al and amorphous Si was investigated. Evolution of polycrystalline silicon with randomly oriented grains as a result of a-Si and Al interaction was revealed. After the in-situ heating experiment the specimen was subjected to high resolution TEM and EDS investigations after removing the excess Al. The EDS analysis of the crystallized specimen was performed to locate the Al distribution in the crystallized silicon. These studies show that the Al induced crystallization process can be used to prepare polycrystalline as well as nanocrystalline silicon by controlling the in-situ annealing parameters. The investigations are very useful as the nanocrystalline silicon is being investigated for its use in developing high efficiency silicon solar structures.

Polytypoids in high Tc thallium based superconducting materials

1990 ◽  
Vol 5 (8) ◽  
pp. 1620-1624
Author(s):  
A. K. Singh ◽  
M. A. Imam ◽  
K. Sadananda ◽  
S. B. Qadri ◽  
E. F. Skelton ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Electron Diffraction Pattern ◽  
Stacking Faults ◽  
Superconducting Materials ◽  
Superconducting Properties ◽  
High Tc ◽  
Transmission Electron

Several high Tc compounds containing Tl (thallium) were prepared starting from different initial compositions. Superconducting properties and the structure were determined for each sample. Electron diffraction and transmission electron microscopy showed the existence of polytypic high Tc compounds with the same a- and b-axes but different c-axis values. The c-axis appears to increase approximately in integral multiples of 0.15 nm with varying composition and is associated with the insertion of Cu–Ca or Cu–Tl layers in each unit cell. Several random stacking faults were also noted, which give rise to diffuse streaking in the electron diffraction pattern.

scholarly journals Approach to observe folded chains of syndiotactic polystyrene on solution-grown crystals by atomic force microscopy

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Nobuyuki Suto ◽  
Atsuhiro Fujimori ◽  
Toru Masuko
Keyword(s):  
Atomic Force Microscopy ◽  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Electron Diffraction Pattern ◽  
Polymer Chains ◽  
Syndiotactic Polystyrene ◽  
Mesoscopic Scale ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

Abstract Folded chains of syndiotactic polystyrene located on the surface of its solution-grown crystals (SGCs) have been observed on nano scale by use of atomic force microscopy (AFM). Transmission electron micrographs of the SGCs on the mesoscopic scale exhibited truncated-lozenge platelets accompanied by a sharp electron diffraction pattern of the β”-form. AFM images of selected areas on the SGC surface indicated folded chains existing periodically on the surface with c. 1.3 to 1.4 nm spacing, suggesting that the polymer chains are aligned in parallel with the {230} growth faces of SGC.

Computer-Aided Indexing and Simulation of Transmission Electron Diffraction Patterns

1975 ◽  
Vol 33 ◽  
pp. 222-223
Author(s):  
Prakash Rao ◽  
R. P. Goehner
Keyword(s):  
Crystal Structure ◽  
Electron Diffraction ◽  
Computer Programs ◽  
Transmission Electron Diffraction ◽  
Lattice Constants ◽  
Transmission Electron ◽  
Computer Aided ◽  
Flow Diagrams ◽  
Diffraction Patterns ◽  
Orientation Determination

The process of indexing electron diffraction patterns is well established and reasonably straightforward. However, in the more complicated crystal systems (e.g. hexagonal, rhombohedral, orthorhombic and monoclinic), indexing and orientation determination is not always simple. In order to considerably ease the tedium of routinely indexing such electron diffraction patterns, automation of the procedure has been carried out in our laboratory by the use of two computer programs written in conversational Fortran.Simplified flow diagrams of the two programs are shown in Figure 1. The first program (Figure 1a) indexes diffraction spots whose x and y coordinates are obtained from an experimental pattern and supplied, along with crystal structure, lattice constants, space group restrictions, camera constant, and the position and angle errors allowable.

HRTEM Study of Precipitates in Al-Mg-Si and Al-Mg-Ge Alloys

2006 ◽  
Vol 519-521 ◽  
pp. 221-226 ◽  
Author(s):  
Kenji Matsuda ◽  
Susumu Ikeno ◽  
Teruyoshi Munekata
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Metastable Phase ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Diffraction Technique

In this work, the crystal structure of the rod-shaped precipitate in aged Al -1.0 mass% Mg2Ge alloy at 523 K has been investigated by high resolution transmission electron microscopy (HRTEM), electron diffraction technique and energy dispersive X-ray spectroscopy (EDS). The rod-shaped precipitate in its alloy has showed the similar arrangement of bright dots in its HRTEM images and selected area diffraction pattern (SADP) to those of the b’-phase in Al-Mg2Si alloy. But a lattice constant of this precipitate in Al-Mg2Ge alloy was slightly larger than the b’-phase in Al-Mg2Si alloy. In addition, the new metastable phase has been found out in Al-Mg-Ge alloy.

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