scholarly journals Modifications of Metallic and Inorganic Materials by Using Ion/Electron Beams

2021 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Akihiro Iwase

Welcome to the Special Issue of Quantum Beam Science entitled “Modifications of Metallic and Inorganic Materials by Using Ion/Electron Beams” [...]

2021 ◽  
Vol 11 (23) ◽  
pp. 11548
Author(s):  
Alberto Dalla Mora

Light is a powerful tool for the non-invasive and non-destructive analysis of several organic and inorganic materials [...]


2013 ◽  
Vol 7 (6) ◽  
pp. 613-613
Author(s):  
Shigeka Yoshimoto ◽  
Toshiharu Tanaka

Highly complex nonsilicon submillimeter microparts such as glass waveguides, microlens arrays and holographic optical elements are coming increasingly into demand. These microparts feature such divergent properties as high hardness, high brittleness and high melting point. Despite the introduction of special technologies such as lithography and components such as lasers and electron beams, these unique properties make them particularly difficult to machine – and this comes at a time when micro manufacturing must provide processes that are maximally effective and efficient while remaining minimally expensive at the same time. These requirements call for innovations in mechanical manufacturing technologies that enable them to realize microfabrication, and these in turn require the discovery and implementation of such new processing principles as M4 – micro/meso mechanical manufacturing. These techniques are now at the frontier of manufacturing technology. The objective of this special issue is to address the latest in research advances, practical and theoretical applications, and various case studies on M4 processes. The papers featured in this issue provide help in development of next-generation manufacturing technologies. We thank the authors for their invaluable contributions and the reviewers for their always useful advice, which make this special issue both fascinating and worthwhile.


Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1120
Author(s):  
Enrico Cavalli

This Special Issue is dedicated to luminescent inorganic materials, an extremely vast topic that often and willingly crosses over into other important fields of chemistry and physics [...]


Author(s):  
D. E. Speliotis

The interaction of electron beams with a large variety of materials for information storage has been the subject of numerous proposals and studies in the recent literature. The materials range from photographic to thermoplastic and magnetic, and the interactions with the electron beam for writing and reading the information utilize the energy, or the current, or even the magnetic field associated with the electron beam.


Author(s):  
Tamotsu Ohno

The energy distribution in an electron; beam from an electron gun provided with a biased Wehnelt cylinder was measured by a retarding potential analyser. All the measurements were carried out with a beam of small angular divergence (<3xl0-4 rad) to eliminate the apparent increase of energy width as pointed out by Ichinokawa.The cross section of the beam from a gun with a tungsten hairpin cathode varies as shown in Fig.1a with the bias voltage Vg. The central part of the beam was analysed. An example of the integral curve as well as the energy spectrum is shown in Fig.2. The integral width of the spectrum ΔEi varies with Vg as shown in Fig.1b The width ΔEi is smaller than the Maxwellian width near the cut-off. As |Vg| is decreased, ΔEi increases beyond the Maxwellian width, reaches a maximum and then decreases. Note that the cross section of the beam enlarges with decreasing |Vg|.


Author(s):  
David J. Smith

The era of atomic-resolution electron microscopy has finally arrived. In virtually all inorganic materials, including oxides, metals, semiconductors and ceramics, it is possible to image individual atomic columns in low-index zone-axis projections. A whole host of important materials’ problems involving defects and departures from nonstoichiometry on the atomic scale are waiting to be tackled by the new generation of intermediate voltage (300-400keV) electron microscopes. In this review, some existing problems and limitations associated with imaging inorganic materials are briefly discussed. The more immediate problems encountered with organic and biological materials are considered elsewhere.Microscope resolution. It is less than a decade since the state-of-the-art, commercially available TEM was a 200kV instrument with a spherical aberration coefficient of 1.2mm, and an interpretable resolution limit (ie. first zero crossover of the contrast transfer function) of 2.5A.


Author(s):  
Patricia G. Arscott ◽  
Gil Lee ◽  
Victor A. Bloomfield ◽  
D. Fennell Evans

STM is one of the most promising techniques available for visualizing the fine details of biomolecular structure. It has been used to map the surface topography of inorganic materials in atomic dimensions, and thus has the resolving power not only to determine the conformation of small molecules but to distinguish site-specific features within a molecule. That level of detail is of critical importance in understanding the relationship between form and function in biological systems. The size, shape, and accessibility of molecular structures can be determined much more accurately by STM than by electron microscopy since no staining, shadowing or labeling with heavy metals is required, and there is no exposure to damaging radiation by electrons. Crystallography and most other physical techniques do not give information about individual molecules.We have obtained striking images of DNA and RNA, using calf thymus DNA and two synthetic polynucleotides, poly(dG-me5dC)·poly(dG-me5dC) and poly(rA)·poly(rU).


Author(s):  
Philippe Pradère ◽  
Edwin L. Thomas

High Resolution Electron Microscopy (HREM) is a very powerful technique for the study of crystal defects at the molecular level. Unfortunately polymer crystals are beam sensitive and are destroyed almost instantly under the typical HREM imaging conditions used for inorganic materials. Recent developments of low dose imaging at low magnification have nevertheless permitted the attainment of lattice images of very radiation sensitive polymers such as poly-4-methylpentene-1 and enabled molecular level studies of crystal defects in somewhat more resistant ones such as polyparaxylylene (PPX) [2].With low dose conditions the images obtained are very noisy. Noise arises from the support film, photographic emulsion granularity and in particular, the statistical distribution of electrons at the typical doses of only few electrons per unit resolution area. Figure 1 shows the shapes of electron distribution, according to the Poisson formula :


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