Investigation of Fe2O3/SiO2 Nanocomposite by Field Emission Scanning Electron Microscopes and Transmission Electron Microscope

2013 ◽  
Vol 19 (11) ◽  
pp. 3253-3256
Author(s):  
B. C. Ang ◽  
I. I. Yaacob ◽  
Irwan Nurdin ◽  
M. R. Johan
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Transmission Electron Microscope ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

The Observation of NBC Precipitates In Steels In The Nanometer Range Using A Field Emission Gun Scanning Electron Microscope

1997 ◽  
Vol 3 (S2) ◽  
pp. 1243-1244 ◽  
Author(s):  
Raynald Gauvin ◽  
Steve Yue
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
Incident Electron Energy ◽  
Beam Diameter ◽  
Probe Diameter ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

The observation of microstructural features smaller than 300 nm is generally performed using Transmission Electron Microscopy (TEM) because conventional Scanning Electron Microscopes (SEM) do not have the resolution to image such small phases. Since the early 1990’s, a new generation of microscopes is now available on the market. These are the Field Emission Gun Scanning Electron Microscope with a virtual secondary electron detector. The field emission gun gives a higher brightness than those obtained using conventional electron filaments allowing enough electrons to be collected to operate the microscope with incident electron energy, E0, below 5 keV with probe diameter smaller than 5 nm. At 1 keV, the electron range is 60 nm in aluminum and 10 nm in iron (computed using the CASINO program). Since the electron beam diameter is smaller than 5 nm at 1 keV, the resolution of these microscopes becomes closer to that of TEM.

The Use of a Lanthanum Hexaboride Filament in a Transmission Electron Microscope - The Philips EM-400

1977 ◽  
Vol 35 ◽  
pp. 64-65 ◽  
Author(s):  
V. R. Mumaw ◽  
B. L. Munger
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Lanthanum Hexaboride ◽  
Electron Source ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

The use of lanthanum hexaboride (LaBg) as an electron source in scanning electron microscopes equipped with an ion pumped emission chamber at less than 10~6 torr, has proven to be very advantageous. It was not until the introduction of the Philips EM-400 that a standard commercially available transmission electron microscope was differentially pumped between the emission chamber and the viewing chamber and capable of achieving a vacuum suitable for utilizing this type of electron source.Only minor modifications were necessary to use the LaBg filament (Kimbal Physics, Wilton, N.H.) in the Philips EM-400 electron microscope. The Wehnelt cap was modified so that the Wehnelt aperture can be removed without disassembly of the cap (Fig. 1). The Wehnelt aperture is 0.7 mm in diameter. A simple spanner wrench is used to remove the Wehnelt aperture. Rough centering of the filament was quite easy using a Zeiss operating stereomicroscope at 25X with the Wehnelt aperture removed.

The Morphology of Obliterative Arterial Diseases in Statu Nascendi

1979 ◽  
Author(s):  
M. Marshall ◽  
J. Staubesand ◽  
H. Hese
Keyword(s):  
Risk Factors ◽  
Electron Microscope ◽  
Blood Platelet ◽  
Arterial Disease ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Mini Pigs ◽  
Scanning Electron ◽  
Blood Platelet Aggregation

The arteries of mini pigs which had been exposed to the local or systemic action of recognised ‘risk factors’ for arterial disease were examined with the light microscope, and the transmission and scanning electron microscopes. Initially the scanning instrument revealed adhesions of platelets in different stages of development, but showed an apparently intact endothelium. With the transmission electron microscope, however, degenerative changes in the endothelium could be observed. Increased blood platelet aggregation was also present. After a few weeks we could see a remarkable focal thickening of the intima, together with deposits on the endothelium of platelets, erythrocytes and fibrin (“mixed microparietal thrombosis”). After 6 months fully developed arteriosclerosis of the abdominal aorta had appeared.

Development of a 1MV-Field-Emission Electron Microscope I. Instrument

2000 ◽  
Vol 6 (S2) ◽  
pp. 1138-1139
Author(s):  
I. Matsui ◽  
T. Katsuta ◽  
T. Kawasaki ◽  
S. Hayashi ◽  
T. Furutsu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Transmission Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
Electron Holography ◽  
Lorentz Microscopy ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Resolution Imaging ◽  
Electron Microscopes

We have developed 100-kV, 200-kV, and 350-kV cold-field-emission transmission electron microscopes (FE-TEMs) successively up to this time. Using these instruments, we have been studying the magnetic structure of materials, high-resolution imaging by electron holography, and dynamic observation of the vortex in superconductors by Lorentz microscopy. To make more progress in our research, we need a better electron beam in terms of coherency, beam brightness, and penetration. Here, we report a new lMV-cold-field-emission transmission electron microscope we have developed. Historically, the pioneering projects on a lMV-field-emission scanning transmission electron microscope (FE-STEM) (Zeitler and Crewe, 1974) and a 1.6MV FE-STEM (Jouffrey et al., 1984) have been reported. In 1988, Maruse and Shimoyama obtained a lMV-field-emission beam using their 1.25MV-STEM connected to a field-emission gun. Since then, continuous improvements in beam brightness has been made.The target specifications of our 1 MV-cold-field-emission TEM (H-1000FT) are as follows: Acceleration voltage: 1MV, high-voltage stability :

scholarly journals Evolution and Comparison of Electron Sources

1993 ◽  
Vol 1 (4) ◽  
pp. 16-17
Author(s):  
Doug Rathkey
Keyword(s):  
Cathode Material ◽  
Field Emission ◽  
Electron Beam Lithography ◽  
Electron Sources ◽  
Thermionic Cathodes ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Field Emission Cathodes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

Over the years, we've seen major developments in electron source technologies in response to the demands for better performance. This article presents a brief overview of the cathode technologies in use today.Two types of electron sources are used in commercially available scanning electron microscopes (SEMs), transmission electron microscopes (TEMs), scanning Auger microprobes, and electron beam lithography systems: thermionic and field emission electron cathodes. Thermionic cathodes reiease electrons from the cathode material when they are heated while field emission cathodes rely on a high electric field to draw electrons from the cathode material.

Ultrastructure Research of the Gastritis from Returning Bile

1990 ◽  
Vol 48 (3) ◽  
pp. 202-203
Author(s):  
Shaopeng Hu ◽  
Jianhua Wang ◽  
Zhen Li ◽  
Huei Chen ◽  
Fei Cu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Gastric Mucosa ◽  
Scanning Electron Microscope ◽  
Lamina Propria ◽  
Transmission Electron Microscope ◽  
Ultrastructural Change ◽  
Common Disease ◽  
Epithelial Surface ◽  
Transmission Electron ◽  
Scanning Electron

Gastritis from returning bile is a common disease, but the reason for the disease is not clear. As the pathologic ultrastructure research progresses, it has drawn attention to the ultrastructural change of cells in gastric mucosa by clinical workers. We observed gastric mucosa tissues of 15 patients suffering from gastritis with a transmission electron microscope (TEM) and a scanning electron microscope (SEM). It is the first report in China that fungus exists in the lamina propria of gastric mucosa tissue. The result is as follows.The gastric mucosa tissues of 15 patients suffering from gastritis were acquired by stomachoscopy. Both TEM and SEM specimens were prepared by the usual methods. Under the TEM, the epithelial surface became higher and larger. Mitochondria of the cells were swollen and cristae were disrupted. There were vacuoles in the cells. The nucleus showed disorder, heterochromatin became darker, and nucleolae could be observed.

Observations of thick and thin sections in a field-emission SEM

1994 ◽  
Vol 52 ◽  
pp. 1018-1019
Author(s):  
W. P. Wergin ◽  
S. Roy ◽  
E. F. Erbe ◽  
C. A. Murphy ◽  
C. D. Pooley
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Room Temperature ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Chemical Fixation ◽  
Thin Sections ◽  
Transmission Electron ◽  
Conventional Transmission Electron Microscope ◽  
Scanning Electron

Larvae of the nematode, Steinernema carpocapsae Weiser strain All, were cryofixed and freezesubstituted for 3 days in acetone containing 2% osmium tetroxide according to established procedures. Following chemical fixation, the nematodes were brought to room temperature, embedded in Spurr's medium and sectioned for observation with a Hitachi S-4100 field emission scanning electron microscope that was equipped with an Oxford CT 1500 Cryotrans System. Thin sections, about 80 nm thick, similar to those generally used in conventional transmission electron microscope (TEM) studies were mounted on copper grids and stained with uranyl acetate for 30 min and lead citrate for 5 min. Sections about 2 μm thick were also mounted and stained in a similar fashion. The grids were mounted on an Oxford grid holder, inserted into the microscope and onto a cryostage that was operated at ambient temperature. Thick and thin sections of the larvae were evaluated and photographed in the SEM at different accelerating voltages. Figs. 4 and 5 have undergone contrast conversion so that the images would resemble transmitted electron micrographs obtained with a TEM.

Remote On-Line Control of a High-Voltage in situ Transmission Electron Microscope with A Rational User Interface

1996 ◽  
Vol 54 ◽  
pp. 384-385
Author(s):  
M.A. O’Keefe ◽  
J. Taylor ◽  
D. Owen ◽  
B. Crowley ◽  
K.H. Westmacott ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
User Interface ◽  
Transmission Electron Microscope ◽  
High Voltage ◽  
Materials Science ◽  
Transmission Electron ◽  
On Line ◽  
Electron Microscopes

Remote on-line electron microscopy is rapidly becoming more available as improvements continue to be developed in the software and hardware of interfaces and networks. Scanning electron microscopes have been driven remotely across both wide and local area networks. Initial implementations with transmission electron microscopes have targeted unique facilities like an advanced analytical electron microscope, a biological 3-D IVEM and a HVEM capable of in situ materials science applications. As implementations of on-line transmission electron microscopy become more widespread, it is essential that suitable standards be developed and followed. Two such standards have been proposed for a high-level protocol language for on-line access, and we have proposed a rational graphical user interface. The user interface we present here is based on experience gained with a full-function materials science application providing users of the National Center for Electron Microscopy with remote on-line access to a 1.5MeV Kratos EM-1500 in situ high-voltage transmission electron microscope via existing wide area networks. We have developed and implemented, and are continuing to refine, a set of tools, protocols, and interfaces to run the Kratos EM-1500 on-line for collaborative research. Computer tools for capturing and manipulating real-time video signals are integrated into a standardized user interface that may be used for remote access to any transmission electron microscope equipped with a suitable control computer.

Application of Transmission Electron Microscope and Scanning Electron Microscope in experimental tumor studies

1990 ◽  
Vol 48 (3) ◽  
pp. 306-307
Author(s):  
Gao Fengming
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Malignant Transformation ◽  
Transmission Electron Microscope ◽  
Experimental Tumor ◽  
Transmission Electron ◽  
Embryo Cells ◽  
Tumor Studies ◽  
Scanning Electron

Transmission electron microscope(TEM) and scanning electron microscope(SEM) were widely used in experimental tumor studies. They are useful for evaluation of cellular transformation in vitro, classification of histological types of tumors and treating effect of tumors. We have obtained some results as follows:1. Studies on the malignant transformation of mammalian cells in vitro. Syrian golden hamster embryo cells(SGHEC) were transformed in vitro by ThO2 and/or ore dust. In a few days after dust added into medium, some dust crystals were phagocytized. Two weeks later, malignant transformation took place. These cells were of different size, nuclear pleomorphism, numerous ribosomes, increasing of microvilli on cell surface with various length and thickness, and blebs and ruffles(Figs. 1,2). Myelomonocytic leukemic transformation of mouse embryo cells(MEC) was induced in vitro by 3H-TdR. Transformed cells were become round from fusiform. The number of mitochondria and endoplasmic reticulum was reduced, ribosomes and nucleoli increased, shape of nuclei irregular, microvilli increased, and blebs and ruffles appeared(Fig. 3).

Sign in / Sign up

Export Citation Format

Share Document