scholarly journals Wide Range Optical Studies on Transparent SWNT Films

Author(s):  
F. Borondics
Keyword(s):  
2018 ◽  
Vol 60 (2) ◽  
pp. 222
Author(s):  
Ю.В. Князев ◽  
А.В. Лукоянов ◽  
Ю.И. Кузьмин ◽  
S. Gupta ◽  
K.G. Suresh

AbstractThe investigations of electronic structure and optical properties of GdRhSn and TbRhSn were carried out. The calculations of band spectrum, taking into account the spin polarization, were performed in a local electron density approximation with a correction for strong correlation effects in 4f shell of rare earth metal (LSDA + U method). The optical studies were done by ellipsometry in a wide range of wavelengths, and the set of spectral and electronic characteristics was determined. It was shown that optical absorption in a region of interband transitions has a satisfactory explanation within a scope of calculations of density of electronic states carried out.


2021 ◽  
Vol 33 (2) ◽  
pp. 291-298
Author(s):  
ANSHU ◽  
MANJU RANI ◽  
SANJEEV MAKEN

Thermophysical properties of binary liquid mixtures are highly beneficial for getting information about the intermolecular interactions and geometrical effects in the system. The chloro-substituted benzene compounds like 2-chlorotoluene, 4-chlorotoluene, 1,3-dichlorobenzene also have wide range of industrial and biomedical areas. In present work, the refractive indices (n) of haloarenes, hydrocarbons, ether, and respective possible binary mixtures were experimentally determined over the entire compositions at T= (298.15-318.15) K. The mixtures selected were 2-chlorotoluene or 4-chlorotoluene or 1,3-dichlorobenzene (1) + n-hexane or cyclohexane or 1,4-dioxane (2) with its possible combinations. The Δn is positive for all binary mixtures at all investigated compositions. Different rules of mixing like Lorentz-Lorentz, Erying-John, Arago-Biot, etc. were also used to predict n values. The Δn values were also analyzed in terms of ongoing intermolecular interactions among the components of the selected system.


1978 ◽  
Vol 79 ◽  
pp. 21-29
Author(s):  
Edwin. L. Turner

Galaxies occur in a wide variety of systems ranging from binary pairs through small groups to rich clusters. These systems in turn possess a wide range of densities, with typical separations between bright (L ≫ L* = 3.4 × 1010 L⊙) galaxies varying from ≲ 10 kpc up to ~ 1 Mpc. Among the most common of these systems are small, loose groups containing ≲ 10 bright galaxies with separations ≳ 100 kpc. Such systems probably contain a substantial fraction of all galaxies (de Vaucouleurs 1975; van den Bergh 1962; Karachentseva 1973). Familiar examples include the Local Group and M81 group.


Author(s):  
R.W. Horne

The technique of surrounding virus particles with a neutralised electron dense stain was described at the Fourth International Congress on Electron Microscopy, Berlin 1958 (see Home & Brenner, 1960, p. 625). For many years the negative staining technique in one form or another, has been applied to a wide range of biological materials. However, the full potential of the method has only recently been explored following the development and applications of optical diffraction and computer image analytical techniques to electron micrographs (cf. De Hosier & Klug, 1968; Markham 1968; Crowther et al., 1970; Home & Markham, 1973; Klug & Berger, 1974; Crowther & Klug, 1975). These image processing procedures have allowed a more precise and quantitative approach to be made concerning the interpretation, measurement and reconstruction of repeating features in certain biological systems.


Author(s):  
E.D. Wolf

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.


Author(s):  
B. J. Hockey

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.


Author(s):  
H. Todokoro ◽  
S. Nomura ◽  
T. Komoda

It is interesting to observe polymers at atomic size resolution. Some works have been reported for thorium pyromellitate by using a STEM (1), or a CTEM (2,3). The results showed that this polymer forms a chain in which thorium atoms are arranged. However, the distance between adjacent thorium atoms varies over a wide range (0.4-1.3nm) according to the different authors.The present authors have also observed thorium pyromellitate specimens by means of a field emission STEM, described in reference 4. The specimen was prepared by placing a drop of thorium pyromellitate in 10-3 CH3OH solution onto an amorphous carbon film about 2nm thick. The dark field image is shown in Fig. 1A. Thorium atoms are clearly observed as regular atom rows having a spacing of 0.85nm. This lattice gradually deteriorated by successive observations. The image changed to granular structures, as shown in Fig. 1B, which was taken after four scanning frames.


Author(s):  
T. Miyokawa ◽  
S. Norioka ◽  
S. Goto

Field emission SEMs (FE-SEMs) are becoming popular due to their high resolution needs. In the field of semiconductor product, it is demanded to use the low accelerating voltage FE-SEM to avoid the electron irradiation damage and the electron charging up on samples. However the accelerating voltage of usual SEM with FE-gun is limited until 1 kV, which is not enough small for the present demands, because the virtual source goes far from the tip in lower accelerating voltages. This virtual source position depends on the shape of the electrostatic lens. So, we investigated several types of electrostatic lenses to be applicable to the lower accelerating voltage. In the result, it is found a field emission gun with a conical anode is effectively applied for a wide range of low accelerating voltages.A field emission gun usually consists of a field emission tip (cold cathode) and the Butler type electrostatic lens.


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