A search-match program for materials identification in the Transmission Electron Microscope using electron diffraction pattern analysis

1990 ◽  
Vol 48 (4) ◽  
pp. 432-433
Author(s):  
S.H. Vale
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Electron Diffraction Pattern ◽  
Pattern Analysis ◽  
Chemical Information ◽  
Large Database ◽  
X Ray ◽  
Colour Image ◽  
Transmission Electron ◽  
Combining Data

A program has been written for an energy dispersive x-ray microanalysis system computer to identify a sample by combining data from an electron diffraction pattern collected in a TEM with chemical information from the sample. The combined information is compared with a large database held on the computer to find a suitable set of matching compounds.The program was written for a Link Analytical AN10000 microanalysis system which is based on a computer with a 16 bit word length, 20 MHz CPU with 512 kbyte of memory for programs and data, 40 Mbyte hard disk and a 512 × 512 pixel colour image display with its own memory. The database used was the NBS/SANDIA/ICDD electron diffraction database adapted for the AN 10000 computer. This database contains about 70000 compound entries and occupies 9 Mbyte of disk space.

The structure of amorphous and polycrystalline materials using energy-filtered RDF analysis

1992 ◽  
Vol 50 (2) ◽  
pp. 1190-1191
Author(s):  
David Cockayne ◽  
David McKenzie
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Density Function ◽  
Electron Diffraction Pattern ◽  
Polycrystalline Materials ◽  
Nearest Neighbour ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Reduced Density ◽  
System F

The technique of Electron Reduced Density Function (RDF) analysis has ben developed into a rapid analytical tool for the analysis of small volumes of amorphous or polycrystalline materials. The energy filtered electron diffraction pattern is collected to high scattering angles (currendy to s = 2 sinθ/λ = 6.5 Å-1) by scanning the selected area electron diffraction pattern across the entrance aperture to a GATAN parallel energy loss spectrometer. The diffraction pattern is then converted to a reduced density function, G(r), using mathematical procedures equivalent to those used in X-ray and neutron diffraction studies.Nearest neighbour distances accurate to 0.01 Å are obtained routinely, and bond distortions of molecules can be determined from the ratio of first to second nearest neighbour distances. The accuracy of coordination number determinations from polycrystalline monatomic materials (eg Pt) is high (5%). In amorphous systems (eg carbon, silicon) it is reasonable (10%), but in multi-element systems there are a number of problems to be overcome; to reduce the diffraction pattern to G(r), the approximation must be made that for all elements i,j in the system, fj(s) = Kji fi,(s) where Kji is independent of s.

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.

Microstructure of Bonding Interface in Explosively Welded Metal/Ceramic Clad

2010 ◽  
Vol 638-642 ◽  
pp. 3775-3780 ◽  
Author(s):  
Seiichiro Ii ◽  
Chihiro Iwamoto ◽  
Shinobu Satonaka ◽  
Kazuyuki Hokamoto ◽  
Masahiro Fujita
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Nitride ◽  
Electron Diffraction ◽  
Electron Diffraction Pattern ◽  
Explosive Welding ◽  
Bonding Interface ◽  
X Ray ◽  
Transmission Electron ◽  
Metal Ceramic

Bonding interface in aluminum (Al) and silicon nitride (Si3N4) clad fabricated by explosive welding has been investigated by transmission electron microscopy (TEM). The nanocrystalline region was clearly observed at the interface between Al and Si3N4. Electron diffraction pattern and energy dispersive X-ray spectroscopy (EDS) measurements across the interface revealed that this nanocrystalline region consist of the only aluminum.

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.

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.

PC based diffraction pattern analysis programs

1988 ◽  
Vol 46 ◽  
pp. 974-975
Author(s):  
A. G. Jackson ◽  
M. Rowe
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Software Package ◽  
Pattern Analysis ◽  
Intermediate Point ◽  
X Ray ◽  
Diffraction Patterns

The analysis of electron diffraction patterns can be done automatically using image techniques for collecting the diffraction pattern. This is useful if the material is well known. The alternative when the material is not well known is to do hand measurements on the plate and then enter that data into a program, or do the entire analysis by hand. We have developed a small software package called CRYSTAL, for a PC/AT which is an intermediate point between the fully automated approach and the approach by hand. These programs were written to be used in conjunction with the EMS programs in order to compare theoretical patterns with those obtained experimentally.The program menu is displayed by typing “CRYSTAL”. There are five choices available from the menu: 1) enter diffraction pattern data using the digitizer, 2) analysis of the zone and planes associated with the measured planes, 3) plot the theoretical diffraction pattern and/or the measured planes, either on the CRT or the plotter, 4) calculate x-ray planes and 20 angles, 5) return to DOS.

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