Development of 200 kV Scanning-Transmission Electron Microscope

1974 ◽  
Vol 32 ◽  
pp. 410-411
Author(s):  
H. Koike ◽  
S. Sakurai ◽  
K. Ueno ◽  
M. Watanabe
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
The Other ◽  
Morphological Observation ◽  
Magnetic Domains ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Backscattered Electron ◽  
Increasing Demand

In recent years, there has been increasing demand for higher voltage SEMs, in the field of surface observation, especially that of magnetic domains, dislocations, and electron channeling patterns by backscattered electron microscopy. On the other hand, the resolution of the CTEM has now reached 1 ∼ 2Å, and several reports have recently been made on the observation of atom images, indicating that the ultimate goal of morphological observation has beem nearly achieved.

On-Line Aberration Measurement and Correction in STEM

1997 ◽  
Vol 3 (S2) ◽  
pp. 1171-1172 ◽  
Author(s):  
Ondrej L. Krivanek ◽  
Niklas Dellby ◽  
Andrew J. Spence ◽  
Roger A. Camps ◽  
L. Michael Brown
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Spherical Aberration ◽  
Computer Control ◽  
Beam Current ◽  
Scanning Transmission Electron Microscope ◽  
Transmission Electron ◽  
Probe Size ◽  
Scanning Transmission ◽  
On Line

Aberration correction in electron microscopy is a subject with a 60 year history dating back to the fundamental work of Scherzer. There have been several partial successes, such as Deltrap's spherical aberration (Cs) corrector which nulled Cs over 30 years ago. However, the practical goal of attaining better resolution than the best uncorrected microscope operating at the same voltage remains to be fulfilled. Combining well-known electron-optical principles with stable electronics, versatile computer control, and software able to diagnose and correct aberrations on-line is at last bringing this goal within reach.We are building a quadrupole-octupole Cs corrector with automated aberration diagnosis for a VG HB5 dedicated scanning transmission electron microscope (STEM). A STEM with no spherical aberration will produce a smaller probe size with a given beam current than an uncorrected STEM, and a larger beam current in a given size probe.

High-resolution backscattered electron images in the scanning electron microscope

1992 ◽  
Vol 50 (2) ◽  
pp. 1608-1609
Author(s):  
Oliver C. Wells ◽  
P.C. Cheng
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Transmission Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
Atomic Resolution ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Backscattered Electron ◽  
Scanning Electron

In this discussion the words “high resolution imaging” of a solid sample in the scanning electron microscope (SEM) mean that details can be resolved that are considerably smaller than the penetration depth of the incident electron beam (EB) into the specimen. “Atomic resolution” in either the transmission electron microscope (TEM) or scanning transmission electron microscope (STEM) means that columns of atoms are resolved.Image contrasts in the backscattered electron (BSE) image are strongly affected by the specimen tilt and by the position and energy sensitivity of the BSE detector. The expression “BSE image” generally implies that the specimen is normal to the beam and the detector is above it. This shows compositional variations in the specimen with a spatial resolution limited by the spreading of the EB during the initial stages of penetration. This is similar in basic principle to the Z-Contrast method in the STEM that shows atomic resolution from a thinned single crystal mounted in the magnetic field of the focusing lens.

Comparison of Scanning Transmission and Backscattered Electron Imaging in the Sem, Using Heavy Metal Stained Sections of Biological Tissue

1976 ◽  
Vol 34 ◽  
pp. 322-323
Author(s):  
Phillip B. DeNee ◽  
Richard G. Frederickson
Keyword(s):  
Heavy Metal ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Light Microscope ◽  
Biological Tissues ◽  
Scanning Transmission Electron Microscope ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Backscattered Electron ◽  
Better Than

The Transmission Electron Microscope (TEM) has been used extensively for the study of biological tissues in thin section (50-100 nm). For sectioned material greater than 100 nm, the Scanning Transmission Electron Microscope (STEM) and the High Voltage Electron Microscope (HVEM) have become the only alternatives for the study of these tissues at a resolution better than that obtained with the light microscope. Recently, it has been shown(1) that tissue stained with heavy metal can be studied in the Scanning Electron Microscope (SEM) by Backscattered Electron (BSE) imaging to give results similar to those obtained with the TEM. Because BSE imaging is a method complementary to STEM, it seemed worthwhile to compare the two techniques using the same specimens and beam conditions.Direct observation of the total specimen is possible with BSE imaging without interference by grid bars. Therefore, an improved perspective of tissue-totissue structural relationships can be obtained at a resolution significantly better than that of the light microscope.

Analytical electron microscopy of fresh and vehicle-aged catalysts

1988 ◽  
Vol 46 ◽  
pp. 714-715
Author(s):  
Sooho Kim
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Analytical Electron Microscopy ◽  
Scanning Transmission Electron Microscope ◽  
Automotive Catalysts ◽  
Area Reduction ◽  
Transmission Electron ◽  
Analytical Electron ◽  
Scanning Transmission

Automotive catalysts have a general loss of activity during aging, basically due to two principal deactivation mechanisms. One of them is thermally induced “sintering,” which results in catalytic surface area reduction. The other is chemically induced “poisoning,” which in part causes blockage of active metal sites. The conventional bulk techniques have indicated that various catalyst functions were affected differently by poisons and thermal damage; however, they generally did not provide detailed descriptions of the mechanisms of deactivation. Only analytical electron microscopy (AEM) can provide microchemical and microstructural information to gain a more thorough and fundamental understanding of catalytic deactivation.Fresh and vehicle-aged commercial automotive catalysts containing Pt, Pd, and Rh on alumina supports were prepared for AEM by a microtomy technique, which retains the spatial integrity of the catalyst pellet with uniform thickness. Then these AEM specimens were characterized in a transmission electron microscope (TEM) and in a dedicated scanning transmission electron microscope (STEM).

A microdiffraction study of Os10C(Co)24-2 in the Scanning Transmission Electron Microscope

1986 ◽  
Vol 44 ◽  
pp. 696-697 ◽  
Author(s):  
M. E. Mochel ◽  
R. I. Masel ◽  
J. M. Mochel
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Structural Information ◽  
Carbon Film ◽  
Scanning Transmission Electron Microscope ◽  
Metal Particles ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Small Metal Particles

Recent papers have discussed some of the difficulties in determining the structure of very small (<10Å) metal particles using electron microscopy. One of the ideas in the literature is that electron diffraction could provide structural information even under conditions where imaging is difficult. The purpose of the work reported here is to demonstrate that one can use electron diffraction techniques to obtain structural information about small metal particles, in this case 5Å osmium particles on a carbon film.

Study of Structural Defects in CdZnTe Crystals by High Resolution Electron Microscopy

2011 ◽  
Vol 1341 ◽  
Author(s):  
A. Hossain ◽  
A. E. Bolotnikov ◽  
G. S. Camarda ◽  
Y. Cui ◽  
R. Gul ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Scanning Transmission Electron Microscope ◽  
Structural Defects ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Scanning Transmission ◽  
Infrared Microscope

ABSTRACTWe investigated defects in CdZnTe crystals produced from various conditions and their impact on fabricated devices. In this study, we employed transmission and scanning transmission electron microscope (TEM and STEM), because defects at the nano-scale are not observed readily under an optical or infrared microscope, or by most other techniques. Our approach revealed several types of defects in the crystals, such as low-angle boundaries, dislocations and precipitates, which likely are major causes in degrading the electrical properties of CdZnTe devices, and eventually limiting their performance.

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