Electron Diffraction of Clay Minerals

1990 ◽  
Author(s):  
Necip Güven
Keyword(s):  
Electron Diffraction ◽  
Clay Minerals

The use of HREM in studying clay minerals

1990 ◽  
Vol 48 (4) ◽  
pp. 490-491
Author(s):  
Quan Qing Chen ◽  
Xing Lu
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Clay Minerals ◽  
High Resolution Electron Microscopy ◽  
Crystal Structure Analysis ◽  
Simulated Image ◽  
Left Handed ◽  
Resolution Electron ◽  
Fine Clay ◽  
Mixed Layers

A wider scope of clay research has been opened by investigators in various branches of science and technology due to their increasing interest in such materials. Electron microscope is one of the important methods for studying clay and clay minerals. Although a previous contribution of electron microscopy was to clarify the morphology and later electron diffraction (ED) of fine clay particles.However with the continous improvement of instrument and high resolution electron microscopy (HREM) techniques has provided more detailed information of clay minerals. This paper presents the use of HREM in stúdying clay minerals among our research.1. Analysis of the structure of clay minerals Recent advances in crystal structure analysis have indicated that disordered features are commonly revealed to various extents in clay mineral structure, such as polytypes,stacking disorders,mixed-layers.......etc. When the fraction of disordered feature is rather low, which cannot be distinguished by other method such as x-ray diffraction,however by using HREM lattice imaging, ED, and computer simulating (CS), which can be distinguished distinctly and sensitively. Fig.1a shows the structure of kaolinite with enantio morphic types i.e. left-handed and right-handed kaolinite. The computer simulated image (CSI) and electron diffraction pattern (EDP) are included for interpretation. It was also found that dickite is exhibited as intergrowth or stacking faults in the koalinite.

Electron Diffraction by Clay Minerals with a Fibrous or Rod-like Habit

Nature ◽  
1951 ◽  
Vol 168 (4270) ◽  
pp. 380-381 ◽  
Author(s):  
D. R. KNAPP ◽  
R. P. MITRA
Keyword(s):  
Electron Diffraction ◽  
Clay Minerals

Electron Diffraction of Wet Biological Membranes

1974 ◽  
Vol 32 ◽  
pp. 158-159
Author(s):  
S.W. Hui ◽  
D.F. Parsons
Keyword(s):  
Electron Diffraction ◽  
Data Collection ◽  
Biological Membranes ◽  
Small Areas ◽  
Electron Diffraction Technique ◽  
Electron Microscopes ◽  
Collection Time ◽  
Camera Length

The development of the hydration stages for electron microscopes has opened up the application of electron diffraction in the study of biological membranes. Membrane specimen can now be observed without the artifacts introduced during drying, fixation and staining. The advantages of the electron diffraction technique, such as the abilities to observe small areas and thin specimens, to image and to screen impurities, to vary the camera length, and to reduce data collection time are fully utilized. Here we report our pioneering work in this area.

Analysis of electron-diffraction intensity profiles using a photodiode-array detection system

1983 ◽  
Vol 41 ◽  
pp. 322-323
Author(s):  
J. B. Warren
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Detection System ◽  
High Energy ◽  
Photographic Emulsion ◽  
Diffraction Intensity ◽  
Silicon Photodiode ◽  
Photodiode Array Detection ◽  
Analog To Digital ◽  
Photodiode Array

Electron diffraction intensity profiles have been used extensively in studies of polycrystalline and amorphous thin films. In previous work, diffraction intensity profiles were quantitized either by mechanically scanning the photographic emulsion with a densitometer or by using deflection coils to scan the diffraction pattern over a stationary detector. Such methods tend to be slow, and the intensities must still be converted from analog to digital form for quantitative analysis. The Instrumentation Division at Brookhaven has designed and constructed a electron diffractometer, based on a silicon photodiode array, that overcomes these disadvantages. The instrument is compact (Fig. 1), can be used with any unmodified electron microscope, and acquires the data in a form immediately accessible by microcomputer.Major components include a RETICON 1024 element photodiode array for the de tector, an Analog Devices MAS-1202 analog digital converter and a Digital Equipment LSI 11/2 microcomputer. The photodiode array cannot detect high energy electrons without damage so an f/1.4 lens is used to focus the phosphor screen image of the diffraction pattern on to the photodiode array.

Electron Diffraction Analysis of Microtwin Structures in Regrown (III) Silicon

1982 ◽  
Vol 40 ◽  
pp. 460-461
Author(s):  
P. Ling ◽  
R. Gronsky ◽  
J. Washburn
Keyword(s):  
Electron Diffraction ◽  
Ion Implantation ◽  
Diffraction Analysis ◽  
Diffraction Pattern ◽  
Direct Consequence ◽  
The Other ◽  
Electron Diffraction Analysis ◽  
Defect Microstructures ◽  
Ion Implanted

The defect microstructures of Si arising from ion implantation and subsequent regrowth for a (111) substrate have been found to be dominated by microtwins. Figure 1(a) is a typical diffraction pattern of annealed ion-implanted (111) Si showing two groups of extra diffraction spots; one at positions (m, n integers), the other at adjacent positions between <000> and <220>. The object of the present paper is to show that these extra reflections are a direct consequence of the microtwins in the material.

Pollutant Identification by Selected Area Electron Diffraction

1974 ◽  
Vol 32 ◽  
pp. 532-533
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson ◽  
C. W. Walker
Keyword(s):  
Thermal Treatment ◽  
Electron Diffraction ◽  
Sample Preparation ◽  
Crystal Structures ◽  
Water Samples ◽  
Environmental Samples ◽  
Short Review ◽  
Selected Area Electron Diffraction ◽  
Multiple Component

Selected area electron diffraction (SAD) has been used successfully to determine crystal structures, identify traces of minerals in rocks, and characterize the phases formed during thermal treatment of micron-sized particles. There is an increased interest in the method because it has the potential capability of identifying micron-sized pollutants in air and water samples. This paper is a short review of the theory behind SAD and a discussion of the sample preparation employed for the analysis of multiple component environmental samples.

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