scholarly journals Application of HVEM to the Study of Radiation Damage in Metals

1973 ◽  
Vol 31 ◽  
pp. 10-11
Author(s):  
J.J. Laidler ◽  
B. Mastel
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Point Defects ◽  
Beam Current ◽  
Crystal Defects ◽  
Continuous Observation ◽  
Irradiation Effects ◽  
High Voltage Electron Microscopy ◽  
Atomic Displacements ◽  
Voltage Electron

One aspect of high voltage electron microscopy, which is normally considered to be a disadvantage in the usual materials studies, is the production of atomic displacements or radiation damage in the specimen. This imposes limitations on beam current, accelerating voltage used or time of observation if one is concerned with measurements which are sensitive to the presence of point defects. This limiting aspect can be turned into a major asset, however, in the case of investigations involving the study of irradiation effects in metals and alloys. The HVEM has a special advantage in such studies, since it makes possible the continuous observation of the accumulation of crystal defects during the process of irradiation.

Detection efficiency and estimation of the performance of high voltage STEM

1978 ◽  
Vol 36 (1) ◽  
pp. 84-85
Author(s):  
A. Ishikawa ◽  
C. Morita ◽  
M. Hibino ◽  
S. Maruse
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Radiation Damage ◽  
High Voltage ◽  
Detection Efficiency ◽  
Beam Current ◽  
High Energy ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Transmission Electron

One of the problems which are met in conventional transmission electron microscopy (CTEM) at high voltages is the reduction of the sensitivity of photographic films for high energy electron beams, resulting in the necessity of using high beam current. This cancels out an advantage of high voltage electron microscopy which is otherwise expected from the reduction of the inelastic scattering in the specimen, that is the reduced radiation damage of the specimen during observations. However, it is expected that the efficiency of the detector of scanning transmission electron microscopy (STEM) can be superior to that of CTEM, since the divergence of the electron beam in the detecting material does not affect the quality of the image. In addition to observation with less radiation damage, high voltage STEM with high detection efficiency is very attractive for observations of weak contrast objects since the enhancement of the contrast (which is an important advantage of STEM) is easily realized electrically.

In Situ Deformation by High Voltage Electron Microscopy

1978 ◽  
Vol 36 (3) ◽  
pp. 355-366
Author(s):  
H. Fujita
Keyword(s):  
Electron Microscopy ◽  
Point Defects ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Structure Sensitive ◽  
Deformation Processes ◽  
Static Electron ◽  
Properties Of Materials ◽  
In Situ Deformation

It is well known that materials are structure-sensitive. This means that properties of materials, especially mechanical properties, are determined by behavior of the lattice imperfections such as dislocations and point defects. High resolution and quick recording of the images by electron microscopy have been effectively used for studying behavior of lattice imperfections. It is very difficult, however, to get a definite conclusion about the deformation processes based on the static electron microscope observation of the dislocation structures formed by deformation, because many processes can be considered to get the same dislocation structure. Therefore, dynamic study of the behavior of lattice imperfections is necessary to carry out in order to investigate the properties of materials.

Review Lecture - Perspectives in high voltage electron microscopy

1974 ◽  
Vol 338 (1612) ◽  
pp. 1-16 ◽  
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Resolving Power ◽  
High Voltage Electron Microscopy ◽  
Fast Electrons ◽  
Gaseous Environment ◽  
Voltage Electron ◽  
New Development ◽  
Visible Effect ◽  
Promising Application

The initial impetus for using higher voltages in electron microscopy came from a desire to examine specimens thicker than could be satisfactorily imaged at 100 kV. Microscopes operating at voltages as high as 3 MV are now in regular use. In metallurgy they are pro­viding valuable information on radiation damage and other dynamic processes. The study of reactions in a controlled gaseous environment is a new development. In biology, much has been learnt about the optimum thickness of specimen for image clarity and information content. A promising application is to the study of the structure of chromosomes. Radiation damage has little visible effect on gross detail in desiccated material, but it limits the observation of living specimens. Attempts are now in progress to attain the higher resolving power made available by the shorter wavelength of fast electrons. The atomic architecture of macromolecules could in theory be laid bare, but it may be confused by radiation damage.

Research on nanoprocess of non-equilibrium materials by in situ ultra-high voltage electron microscopy

Microscopy ◽  
2020 ◽  
Vol 69 (6) ◽  
pp. 331-339
Author(s):  
Hidehiro Yasuda ◽  
Kazuhisa Sato ◽  
Hirotaro Mori
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
High Voltage ◽  
Materials Science ◽  
In Situ Observation ◽  
Irradiation Effects ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Non Equilibrium

Abstract Ultra-high voltage electron microscopy is useful for research utilizing high-penetration thickness of electron beam, in situ observation, or irradiation effects by the particle characteristics of electrons. In this review, the importance of non-equilibrium materials science research by a combination with irradiation effects and in situ observation is shown, and examples of some research are introduced. For example, crystal-amorphous-crystalline phase transition in intermetallic compounds, non-equilibrium phase transition in pure metallic nanoparticles and nucleation and growth process of electron irradiation-induced crystallization in amorphous nanoparticles will be discussed. Finally, we want to suggest the importance of exploring non-equilibrium materials science based on dynamic structures which has been unexplored.

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