ChemInform Abstract: Electron Microscopy, Neutron Diffraction, and Physical Properties of Bi4Sr8Cu5O19+y.

ChemInform ◽  
2010 ◽  
Vol 23 (1) ◽  
pp. no-no
Author(s):  
M. T. CALDES ◽  
J. M. NAVARRO ◽  
F. PEREZ ◽  
M. CARRERA ◽  
J. FONTCUBERTA ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Neutron Diffraction ◽  
Physical Properties

Electron microscopy, neutron diffraction, and physical properties of bismuth strontium copper oxide (Bi4Sr8Cu5O19+y)

1991 ◽  
Vol 3 (5) ◽  
pp. 844-852 ◽  
Author(s):  
M. T. Caldes ◽  
J. M. Navarro ◽  
F. Perez ◽  
M. Carrera ◽  
J. Fontcuberta ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Neutron Diffraction ◽  
Physical Properties ◽  
Copper Oxide ◽  
Strontium Copper Oxide

The Infection of Cells by Bullet-Shaped Viruses

1969 ◽  
Vol 27 ◽  
pp. 372-373
Author(s):  
Frederick A. Murphy ◽  
Alyne K. Harrison ◽  
Sylvia G. Whitfield
Keyword(s):  
Electron Microscopy ◽  
Physical Properties ◽  
Host Cell ◽  
Thin Section ◽  
Cultured Cells ◽  
Cell Infection ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Section Electron Microscopy

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.

A study of oxygen and vacancy ordering in YBa2Cu3O7−x

1989 ◽  
Vol 47 ◽  
pp. 164-165
Author(s):  
Y. P. Lin ◽  
A. H. O’Reilly ◽  
J. E. Greedan ◽  
M. Post
Keyword(s):  
Electron Microscopy ◽  
Neutron Diffraction ◽  
Oxygen Content ◽  
Carbon Film ◽  
Nitrogen Atmosphere ◽  
Vacancy Ordering ◽  
Powder Samples ◽  
Vacancy Chains ◽  
Chain Ordering

In the basal planes of the orthorhombic YBa2Cu3O7-X compound with x=0.07, which has a Tc of around 90K, chains of copper-oxygen are formed along the [010] direction. Previous investigations on the variation of Tc with oxygen content have shown the existence of a plateau at Tc = 60K for x=0.3 to 0.4, suggesting the presence of a separate phase. This phase has also been identified to be orthorhombic, but with a 2x superlattice along [100] of the parent structure, and the superlattice has been attributed to the formation of alternating copper-oxygen and copper-vacancy chains. In our work, we have studied the chain ordering phenomenon by electron microscopy and neutron diffraction on samples with different oxygen contents. We report here some of our electron microscopy findings for samples with x=0.4.Powder samples of YBa2Cu3O7-X were prepared by controlled re-oxidation of previously reduced material. For electron microscopy, the sample was dry ground using a mortar and pestle in a dry nitrogen atmosphere without the use of any solvent and transferred dry onto holey carbon film for examination in a Philips CM12 microscope.

scholarly journals Fabrication and Physical Properties of Single-Crystalline Βeta-FeSi2 Nanowires

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Chih-Yung Yang ◽  
Shu-Meng Yang ◽  
Yu-Yang Chen ◽  
Kuo-Chang Lu
Keyword(s):  
Electron Microscopy ◽  
Physical Properties ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Field Emitters ◽  
Transmission Electron ◽  
Single Source Precursor ◽  
Carrier Gases

Abstract In this study, self-catalyzed β-FeSi2 nanowires, having been wanted but seldom achieved in a furnace, were synthesized via chemical vapor deposition method where the fabrication of β-FeSi2 nanowires occurred on Si (100) substrates through the decomposition of the single-source precursor of anhydrous FeCl3 powders at 750–950 °C. We carefully varied temperatures, duration time, and the flow rates of carrier gases to control and investigate the growth of the nanowires. The morphology of the β-FeSi2 nanowires was observed with scanning electron microscopy (SEM), while the structure of them was analyzed with X-ray diffraction (XRD) and transmission electron microscopy (TEM). The growth mechanism has been proposed and the physical properties of the iron disilicide nanowires were measured as well. In terms of the magnetization of β-FeSi2, nanowires were found to be different from bulk and thin film; additionally, longer β-FeSi2 nanowires possessed better magnetic properties, showing the room-temperature ferromagnetic behavior. Field emission measurements demonstrate that β-FeSi2 nanowires can be applied in field emitters.

Examination of whewellite kidney stones by scanning electron microscopy and powder neutron diffraction techniques

2009 ◽  
Vol 42 (1) ◽  
pp. 109-115 ◽  
Author(s):  
Michel Daudon ◽  
Dominique Bazin ◽  
Gilles André ◽  
Paul Jungers ◽  
Alain Cousson ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Neutron Diffraction ◽  
Kidney Stones ◽  
Structural Characteristics ◽  
Calcium Oxalate Monohydrate ◽  
Atomic Scale ◽  
Mesoscopic Scale ◽  
Powder Neutron Diffraction ◽  
Scanning Electron

Kidney stones made of whewellite,i.e.calcium oxalate monohydrate, exhibit various morphological aspects. The crystalline structure of whewellite at the atomic scale was revisited through a single-crystal neutron study at room temperature using a four-circle automated diffractometer. The possible relationships between the various morphological types of whewellite stones and their structural characteristics were examined at the mesoscopic scale by the use of scanning electron microscopy and at the nanometric scale by powder neutron diffraction. All types of whewellite stones displayed a similar structure at the nanometric scale. However, significant differences were found at the mesoscopic scale. In particular, the crystallites in kidney stones resulting from a genetic hyperoxaluria exhibited a peculiar structure. There was a close relationship between stone morphology and crystallite organization at the mesoscopic level and the effectiveness of extracorporeal shockwave lithotripsy.

Investigations of dc electrical properties in electron-beam modified carbon nanotube films: single- and multiwalled

2005 ◽  
Vol 887 ◽  
Author(s):  
Sanju Gupta ◽  
N. D. Smith ◽  
R. J. Patel ◽  
R. E. Giedd
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Electron Beam ◽  
Physical Properties ◽  
Electron Beam Irradiation ◽  
Carbon Materials ◽  
Nanostructured Carbon ◽  
Beam Irradiation ◽  
Space Applications ◽  
The Family

ABSTRACTCarbon nanotubes (CNTs) in the family of nanostructured carbon materials are of great interest because of several unique physical properties. For space applications, it needs to be shown that CNTs are physically stable and structurally unaltered when subjected to irradiation becomes indispensable. The CNT films were grown by microwave Carbon nanotubes (CNTs) in the family of nanostructured carbon materials are of great interest because of several unique physical properties. For space applications, it needs to be shown that CNTs are physically stable and structurally unaltered when subjected to irradiation becomes indispensable. The CNT films were grown by microwave plasma-assisted chemical vapor deposition (MWCVD) technique using Fe as catalyst. Synthesis of both single- and multiwalled CNTs (SW and MW, respectively) were achieved by varying the thickness of the Fe catalyst layer. To investigate the influence of electron-beam irradiation, CNTs were subjected to low and/or medium energy electron-beam irradiation continuously for a few minutes to several hours. The CNT films prior to and post-irradiation were assessed in terms of their microscopic structure and physical properties to establish property-structure correlations. The characterization tools used to establish such correlations include scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), Raman spectroscopy (RS), and current versus voltage (I-V) measuring contact resistance (two-probe) and dc conductivity (four-probe) properties. Dramatic improvement in the I-V properties for single-walled (from semiconducting to quasi-metallic) and relatively small but systematic behavior for multi-walled (from metallic to more metallic) with increasing irradiation hours is discussed in terms of critical role of defects. Alternatively, contact resistance of single-walled nanotubes decreased by two orders of magnitude on prolonged E-beam exposures. Moreover, these findings provided onset of saturation and damage/degradation in terms of both the electron beam energy and exposure times. Furthermore, these studies apparently brought out a contrasting comparison between mixed semiconducting/metallic (single-walled) and metallic (multiwalled) nanotubes in terms of their structural modifications due to electron-beam irradiation.

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