Specimen Preparation, Special Techniques, and Applications of the Scanning Electron Microscope

1975 ◽  
pp. 211-262 ◽  
Author(s):  
D. E. Newbury ◽  
H. Yakowitz
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Specimen Preparation ◽  
Scanning Electron

Comparison of freeze-fractured yeast replicas using conventional TEM and low-voltage field-emission SEM

1989 ◽  
Vol 47 ◽  
pp. 74-75
Author(s):  
William P. Wergin ◽  
Eric F. Erbe ◽  
Terrence W. Reilly
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Field Emission ◽  
Low Voltage ◽  
Objective Lens ◽  
Specimen Preparation ◽  
Lens System ◽  
Air Drying ◽  
Preparation Techniques ◽  
Scanning Electron

Although the first commercial scanning electron microscope (SEM) was introduced in 1965, the limited resolution and the lack of preparation techniques initially confined biological observations to relatively low magnification images showing anatomical surface features of samples that withstood the artifacts associated with air drying. As the design of instrumentation improved and the techniques for specimen preparation developed, the SEM allowed biologists to gain additional insights not only on the external features of samples but on the internal structure of tissues as well. By 1985, the resolution of the conventional SEM had reached 3 - 5 nm; however most biological samples still required a conductive coating of 20 - 30 nm that prevented investigators from approaching the level of information that was available with various TEM techniques. Recently, a new SEM design combined a condenser-objective lens system with a field emission electron source.

A Biological Cryosystem for the Scanning Electron Microscope

1990 ◽  
Vol 48 (1) ◽  
pp. 414-415
Author(s):  
Zhang zhaohua ◽  
Luo Dong ◽  
Guo Yisong
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Natural State ◽  
Specimen Preparation ◽  
Cold Stage ◽  
Specimen Temperature ◽  
Successful Design ◽  
Scanning Electron

Since early 1970's the use of cold stage on SEM for observation of hydrated samples in their natural state has become more and more popular despite its high cost. Experiences gained from earlier experiments indicate that a successful design should incorporate thefollowing features:1. The specimen temperature should be below −135°C (the recrystallization point of water), lower the temperature, better the results.2. The frozen specimen, the cold block in the specimen preparation chamber, as well as the cold stage should be kept under vacuum at all times to keep them frost free.3. Different specimen preparation processes such as fracturing, coating and sublimation should be possible in one compact preparation chamber .

Microdiffraction phase identification in the scanning electron microscope (SEM)

2004 ◽  
Vol 19 (2) ◽  
pp. 100-103 ◽  
Author(s):  
R. P. Goehner ◽  
J. R. Michael
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Beam Current ◽  
Electron Diffraction Data ◽  
Specimen Preparation ◽  
Phase Identification ◽  
Electron Backscattered Diffraction ◽  
Backscattered Electron ◽  
Ccd Detectors ◽  
Scanning Electron

The identification of crystallographic phases in the scanning electron microscope (SEM) has been limited by the lack of a simple way to obtain electron diffraction data of an unknown while observing the microstructure of the specimen. With the development of charge coupled device (CCD)-based detectors, backscattered electron Kikuchi patterns, alternately referred to as electron backscattered diffraction (EBSD) patterns, can be easily collected. Previously, EBSD has been limited to crystallographic orientation studies due to the poor pattern quality collected with video rate detector systems. With CCD detectors, a typical EBSD can now be acquired from a micron or submicron sized crystal using an exposure time of 1–10 s with an accelerating voltage of 10–40 kV and a beam current as low as 0.1 nA. Crystallographic phase analysis using EBSD is unique in that the properly equipped SEM permits high magnification images, EBSDs, and elemental information to be collected from bulk specimens. EBSD in the SEM has numerous advantages over other electron beam-based crystallographic techniques. The large angular view (∼70°) provided by EBSD and the ease of specimen preparation are distinct advantages of the technique. No sample preparation beyond what is commonly used for SEM specimens is required for EBSD.

scholarly journals A Review Of The Development Of Scanning Electron Microscopy At High Chamber Pressure

1997 ◽  
Vol 5 (1) ◽  
pp. 14-15
Author(s):  
Vivian Robinson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Chamber Pressure ◽  
Natural State ◽  
Specimen Preparation ◽  
Electron Microscopes ◽  
Reproducible Manner ◽  
Scanning Electron

Ever since electron microscopes were developed, it has been the goal of microscopists to observe specimens in their natural state, free from artefacts which can often be introduced through specimen preparation. For most biological specimens, that includes the presence of water. With a pressure of 10-4 torr or lower required to operate a scanning electron microscope (SEM), liquid water, which required a pressure of above 5 torr, was clearly a problem.Although several attempts had been made to examine hydrated specimens in a SEM, the first published results of water imaged in a stable and reproducible manner in the SEM, were presented at the Eighth International Congress on Electron Microscopy in Canberra in 1974 (Robinson, 1974).

scholarly journals SEM/EDS observations of impurities in polar ice: artifacts or not?

2003 ◽  
Vol 49 (165) ◽  
pp. 184-190 ◽  
Author(s):  
Ian Baker ◽  
Daniel Cullen
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Specimen Preparation ◽  
Polar Ice ◽  
Series Of Experiments ◽  
Scanning Electron

AbstractA series of experiments was undertaken to determine the origin of filaments found in grain boundaries and impurity spots found in grain interiors of polar ice during observation in the scanning electron microscope. It is shown that although the filaments are artifacts, they demonstrate the presence of impurities segregated to the grain boundary planes. It is also demonstrated that the impurities observed in the grain interior reside there and were not transported from the grain boundaries during specimen preparation or observation.

Conformational Study of trna, Using the High Resolution Scanning Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 254-255
Author(s):  
J. Langmore ◽  
J. Wall
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Carbon Film ◽  
Dark Field ◽  
Specimen Preparation ◽  
Thin Carbon ◽  
Thin Carbon Film ◽  
The Moment ◽  
Scanning Electron

Individual molecules of yeast transfer RNA have been observed in the elastic dark field, inelastic dark field and “Z contrast” modes of the 5 Å high resolution scanning electron microscope. The operation, and contrast forming abilities of this instrument, are discussed elsewhere.Of particular interest here is the fact that the contrast in this microscope is very high, so that negative staining techniques are not required. This does, however, present a problem in specimen preparation. The single tRNA molecules are approximately 30 Å thick and 50 to 150 Å long and are supported only by a thin carbon film. Difficulties are being experienced at the moment in preserving the structure of the molecules during the specimen preparation stage.

Secondary-Electron imaging by Scintillating Gaseous Detection Device

1992 ◽  
Vol 50 (2) ◽  
pp. 1302-1303 ◽  
Author(s):  
G. D. Danilatos
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Secondary Electron ◽  
Environmental Scanning Electron Microscope ◽  
Environmental Scanning ◽  
Specimen Preparation ◽  
Additional Signal ◽  
Gaseous Environment ◽  
Electron Imaging ◽  
Scanning Electron

The environmental scanning electron microscope (ESEM) incorporates the functions of the conventional SEM while it has the added capability of allowing the examination of virtually any specimen in a gaseous environment. The main modes of imaging are all represented in the ESEM, and some developments with regard to the secondary electron (SE) mode are reported herewith.The conventional E-T detector fails to operate in the gaseous conditions of ESEM, but this obstacle has been overcome with the advent of a gaseous detection device (GDD). The principle of operation of this device is based on the monitoring of the products of interaction between signals and gas. Initially, the ionization from the signal/gas interaction was used to produce images of varying contrast and, later, the gaseous scintillation, from the same interaction, was also used to produce images. First, a low bias was applied to various electrodes but later a much higher bias was used for the purpose of achieving additional signal gain. By careful shaping and positioning the respective electrode, it was shown that SE imaging is possible in the ESEM. This has been also independently demonstrated by use of a special specimen preparation.

“Interpretation of Micrographs from a Scanning Electron Microscope”

1969 ◽  
Vol 27 ◽  
pp. 22-23
Author(s):  
E. Eichen ◽  
D. R. Fitchmun ◽  
L. R. Sefton
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Rough Surface ◽  
Great Increase ◽  
Depth Of Field ◽  
Specimen Preparation ◽  
The Past ◽  
The World ◽  
Voltage Contrast ◽  
Scanning Electron

In the past two years, there has been a great increase in interest in the scanning electron microscope as a research tool. Coupled with this has been a large increase in the number of instruments being used throughout the world. The reasons for this popularity stems from the unique abilities of this form of in strumentation which include: (a) a large depth of field which allows one to view a very rough surface; (b) a minimal requirement of specimen preparation; and (c) its ability to make use of voltage contrast in the study of semiconductors.

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