The improved method of obtaining crystals with a small number of linear defects

1974 ◽

Vol 32 ◽

pp. 402-403

Author(s):

S. Nakahara ◽

D. M. Maher

Keyword(s):

Image Analysis ◽

Computational Approach ◽

Dislocation Loops ◽

Plane Wave Expansion ◽

Dynamical Equations ◽

Bloch Waves ◽

Linear Defects ◽

Imperfect Crystal ◽

Localized Defects ◽

Defective Crystals

Since Head first demonstrated the advantages of computer displayed theoretical intensities from defective crystals, computer display techniques have become important in image analysis. However the computational methods employed resort largely to numerical integration of the dynamical equations of electron diffraction. As a consequence, the interpretation of the results in terms of the defect displacement field and diffracting variables is difficult to follow in detail. In contrast to this type of computational approach which is based on a plane-wave expansion of the excited waves within the crystal (i.e. Darwin representation ), Wilkens assumed scattering of modified Bloch waves by an imperfect crystal. For localized defects, the wave amplitudes can be described analytically and this formulation has been used successfully to predict the black-white symmetry of images arising from small dislocation loops.

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An Improved Method for the Preparation and TEM Examination of Sharp Pointed Tips used in APFIM and STM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100134107 ◽

1990 ◽

Vol 48 (2) ◽

pp. 102-103

Author(s):

E.A. Fischione ◽

P.E. Fischione ◽

J.J. Haugh ◽

M.G. Burke

Keyword(s):

Atom Probe ◽

Preparation Process ◽

Improved Method ◽

Ion Milling ◽

Polishing Process ◽

Probe Field ◽

Scanning Tunnelling ◽

Stm Tips ◽

Tunnelling Microscopy ◽

Ion Microscopy

A common requirement for both Atom Probe Field-Ion Microscopy (APFIM) and Scanning Tunnelling Microscopy (STM) is a sharp pointed tip for use as either the specimen (APFIM) or the probe (STM). Traditionally, tips have been prepared by either chemical or electropolishing techniques. Recently, ion-milling has been successfully employed in the production of APFIM tips [1]. Conventional electropolishing techniques are applicable to a wide variety of metals, but generally require careful manual adjustments during the polishing process and may also be time-consuming. In order to reduce the time and effort involved in the preparation process, a compact, self-contained polishing unit has been developed. This system is based upon the conventional two-stage electropolishing technique in which the specimen/tip blank is first locally thinned or “necked”, and subsequently electropolished until separation occurs.[2,3] The result of this process is the production of two APFIM or STM tips. A mechanized polishing unit that provides these functions while automatically maintaining alignment has been designed and developed.

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Immunoelectron microscopic localization of elastic tissue in archival material using an improved method

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100161539 ◽

1990 ◽

Vol 48 (3) ◽

pp. 794-795

Author(s):

J. C. Fanning ◽

J. F. White ◽

R. Polewski ◽

E. G. Cleary

Keyword(s):

Normal Animal ◽

Animal Tissue ◽

Elastic Tissue ◽

Human Tissues ◽

Improved Method ◽

Tissue Samples ◽

Archival Material ◽

Immuno Electron Microscopy ◽

Arteries And Veins ◽

Biochemical Examination

Elastic tissue is an important component of the walls of arteries and veins, of skin, of the lungs and in lesser amounts, of many other tissues. It is responsible for the rubber-like properties of the arteries and for the normal texture of young skin. It undergoes changes in a number of important diseases such as atherosclerosis and emphysema and on exposure of skin to sunlight.We have recently described methods for the localizationof elastic tissue components in normal animal and human tissues. In the study of developing and diseased tissues it is often not possible to obtain samples which have been optimally prepared for immuno-electron microscopy. Sometimes there is also a need to examine retrospectively samples collected some years previously. We have therefore developed modifications to our published methods to allow examination of human and animal tissue samples obtained at surgery or during post mortem which have subsequently been: 1. stored frozen at -35° or -70°C for biochemical examination; 2.

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