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Surveying Battery Cell Sections To Determine The Composition And Spatial Distribution Of Discharge Products Using An Automated Microprobe, B. M. England, M. T. Frost, I. R. Harrowfield, C. M. Macrae, D. A. J. Swinkels, K. E. Turner, C. B. Ward

Scanning Electron Microscopy

Determining the spatial distribution and composition of hydrohetaerolite in polished sections of discharged Leclanché cells requires the measurement of oxygen concentrations on microcrystalline material. This can be done if the composition of the mounting medium is included in the matrix correction of raw intensities. The method of Pouchou and Pichoir (PAP) is used initially to correct raw intensities obtained from surveys of microcrystalline standard material. Mean analyses agree well with the known compositions provided a correction is made for the oxygen content of the mounting medium. The same correction is then applied to the raw data collected when surveying cell …

A New Surface Analytical Technique With Ion And Laser Beams, Christopher H. Becker

Scanning Electron Microscopy

This paper reviews recent results and developments, while presenting some new information, regarding the development of a novel surface analytical technique that uses nonresonant multiphoton ionization (MPI) of neutral atoms and molecules sputtered by an ion beam, or desorbed by an electron or second laser beam or by thermal means. In this method, called surface analysis by laser ionization (SALI), the nonresonant MPI, or "laser ionization," is coupled with state-of-the-art time-of-flight mass spectrometry to provide extremely sensitive, general, and readily quantifiable surface analysis. A discussion also describes the favorable prospects for implementation of SALI with submicron dimension liquid metal ion …

Freeze-Dried Embedded Specimens For Biological Microanalysis, L. Edelmann

Scanning Electron Microscopy

The main problems associated with freeze-drying of biological material for electron microscopy concern the freeze-drying temperatures and times necessary to minimize artifacts. Due to the many parameters involved these problems have to be resolved experimentally. It can be shown that good morphological preservation of chemically unfixed material is possible when freeze-drying is done exclusively in a temperature range between -80°C and -50°C. OsO₄ vapour fixation of the freeze-dried tissue is not necessary and should be avoided because it may cause ion redistribution artifacts. Embedding at low temperature of properly freeze-dried material does not seem to disturb structure and ion …

Intrauterine Device (Iud) Associated Pathology: A Review Of Pathogenic Mechanisms, Waldemar A. Schmidt, Karmen L. Schmidt

Scanning Electron Microscopy

This paper summarizes our studies of IUD-related disease with those previously published by others. Our data are based upon 51 IUDs and 42 index cases of IUD-related disease demonstrating specific processes. Gross, dissecting microscope, scanning electron microscope and X-ray microanalysis examinations were made of selected IUDs and associated tissues. Tissue associated with the IUDs revealed inflammation in 59.4%, calcific material in 6.3% and no abnormality in 34.4%. JUD-associated tissue responses were accompanied by changes of the IUD; these changes involved deposition of substances upon the IUD surface and degradation of the JUD itself. Disintegration of the IUD, its string or …

The Cathodoluminescence Mode Of The Scanning Electron Microscope: A Powerful Microcharacterization Technique, D. B. Holt, F. M. Saba

Scanning Electron Microscopy

By detecting cathodoluminescence (CL) in a scanning electron microscope (SEM), pan and monochromatic micrographs and CL spectral analyses analogous to x-ray mode point analyses can be obtained. Complete microcharacterization requires alternate examination of both micrographs and spectra. New techniques for near infra-red CL and low-temperatures to produce sharp spectra are of increasing importance. CL emission is due to electron transitions between quantum mechanical states so the radiative defects present can be unambiguously identified at liquid helium temperatures. Strongly luminescent impurities can be detected to below one part in 10⁸. This is 10⁴ times as sensitive as the …

Secondary Electron Imaging In The Scanning Transmission Electron Microscope, R. M. Allen

Scanning Electron Microscopy

The detailed correlation of surface morphology and subsurface microstructure has been made possible by the scanning transmission electron microscope. This instrument provides the capability for simultaneous and independent secondary electron and transmitted electron imaging from the same sample area. This includes the ability to generate mixed secondary/transmitted electron images, which form a concise visual presentation of the information in the two component images.

Correlative surface and through-volume specimen examination of this type has most frequently been applied to backthinned samples, which are specifically prepared in a way which produces electron-transparent material in the immediate vicinity of a surface of interest …

Progress In Element Analysis On A High-Voltage Electron Microscope, W. F. Tivol, D. Barnard, T. Guha

Scanning Electron Microscopy

X-Ray microprobe (XMA) and electron energy-loss (EELS) spectrometers have been installed on the high-voltage electron microscope (HVEM). The probe size has been measured and background reduction is in progress for XMA and EELS as are improvements in electron optics for EELS and sensitivity measurements.

XMA is currently useful for qualitative analysis and has been used by several investigators from our laboratory and outside laboratories. However, EELS background levels are still too high for meaningful results to be obtained. Standards suitable for biological specimens are being measured, and a library for quantitative analysis is being compiled.

Energy Selecting Electron Microscopy, F. P. Ottensmeyer

Scanning Electron Microscopy

One of the major improvements in transmission electron microscopy over the last years is the addition of the capability of producing images with electrons that have specific narrow energy bands out of the total spectrum of energies they possess after having passed through the specimen. Though the idea is not new, the power of this application is only beginning to be recognized. Most simply, selection of elastically scattered electrons permits increased contrast in high resolution i mages in bright field, dark field, and diffraction. The use of combined elastic and inelastic signals adds entirely new contrast mechanisms, partially independent of …

Electron Energy Loss Microspectroscopy And The Characterization Of Solids, Richard Leapman

Scanning Electron Microscopy

The inelastic scattering of fast electrons provides a detailed means of characterizing the chemical composition and electronic properties of thin samples in an electron microscope. Collective and single-electron excitations occuring in the low energy region of the spectrum can be described in terms of the generalized dielectric formulation. Important information is contained in this part of the spectrum but some prior detailed knowledge of the sample is usually required for proper interpretation. The core excitations allow microanalytical information to be obtained and quantitative procedures are now quite well developed at least for K and L edges. Sample thickness is one …