scholarly journals Correlative Microscopy Using TEM and SIMS: Parallel Ion Electron Spectrometry (PIES) for High-Resolution, High-Sensitivity Elemental Mapping for Applications in Materials Science and Biology

2014 ◽  
Vol 20 (S3) ◽  
pp. 970-971
Author(s):  
Santhana Eswara Moorthy ◽  
David Dowsett ◽  
Tom Wirtz
Keyword(s):  
High Resolution ◽  
Materials Science ◽  
High Sensitivity ◽  
Elemental Mapping ◽  
Correlative Microscopy ◽  
Electron Spectrometry

High-Resolution Analytical Microscopy in the Center for Materials Science and Engineering at MIT

1997 ◽  
Vol 3 (S2) ◽  
pp. 281-282
Author(s):  
Anthony J. Garratt-Reed
Keyword(s):  
High Resolution ◽  
Materials Science ◽  
High Sensitivity ◽  
Pearlitic Steel ◽  
Diffusion Profile ◽  
Science And Engineering ◽  
Growth Interface ◽  
X Ray ◽  
Analytical Microscopy ◽  
Materials Science And Engineering

The Center for Materials Science and Engineering at MIT, a Materials Research Science and Engineering Center sponsored by the National Science Foundation, maintains and supports, amongst others, an Electron Microscopy Shared Experimental Facility. The purpose of this paper is to highlight selected recent research results for high-resolution investigations performed in that facility.The facility owns the first VG HB603 intermediate-voltage FEG-STEM, which operates at 250KeV and is equipped with a high-solid-angle x-ray detector and a Gatan Digi-Peels. It was intended to be, and has been, used for high sensitivity, high spatial resolution microanalysis. It is well-known that the “resolution” of an x-ray analysis is intimately (and inversely) related to its sensitivity; one extreme situation occurs when analyzing, for example, a diffusion profile, when the need is to determine the composition to the highest precision. An example of such an analysis is given in fig. 1. In this case, the sample is a 1.4Cr-0.8C pearlitic steel, and the chromium analysis is carried out across a cementite plate. During the growth of the pearlite, the chromium, which is not thermodynamically required to redistribute, nevertheless diffuses along the growth interface towards the cementite, resulting in a comparatively wide depletion profile in the ferrite, and a very narrow enrichment in the cementite.

scholarly journals SIMS Based Correlative Microscopy for High-Resolution High-Sensitivity Nano-Analytics

2014 ◽  
Vol 20 (S3) ◽  
pp. 966-967 ◽  
Author(s):  
T. Wirtz ◽  
D. Dowsett ◽  
S. Eswara Moorthy ◽  
Y. Fleming
Keyword(s):  
High Resolution ◽  
High Sensitivity ◽  
Correlative Microscopy

Fast, High-Resolution X-ray Microfluorescence Imaging

1990 ◽  
Vol 34 ◽  
pp. 217-221 ◽  
Author(s):  
D. A. Carpenter ◽  
M. A. Taylor
Keyword(s):  
High Resolution ◽  
Nondestructive Evaluation ◽  
Materials Science ◽  
Solid Angle ◽  
High Sensitivity ◽  
Element Distribution ◽  
Beam Power ◽  
X Rays ◽  
X Ray ◽  
Spatially Resolved

X-ray micro fluorescence imaging refers to the use of an x-ray beam as a probe to excite XRF in a specimen and produce a spatially resolved image of the element distribution. The advantages of high sensitivity and low background, together with the nondestructive nature of the measurement, have lead to applications of x-ray microfluorescence analysis in biology, geology, materials science, as well as in the area of nondestructive evaluation. Previous reports have described the development of an x-ray microprobe which uses a conventional source of x-rays to produce a 10-μm beam. This paper describes improvements to the microprobe which have increased the beam power and the solid angle of detection. The data collection and display software have also been enhanced.

Correlative Microscopy Using SIMS For High-Sensitivity Elemental Mapping

2013 ◽  
Vol 19 (S2) ◽  
pp. 356-357 ◽  
Author(s):  
T. Wirtz ◽  
D. Dowsett ◽  
N. Vanhove ◽  
Y. Fleming
Keyword(s):  
High Sensitivity ◽  
Elemental Mapping ◽  
Correlative Microscopy

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

Backscattered Electron Imaging of GaAs/AlGaAs Super Lattice Structures with an Ultra-High- Resolution SEM

1988 ◽  
Vol 46 ◽  
pp. 204-205
Author(s):  
Kazumichi Ogura ◽  
Michael M. Kersker
Keyword(s):  
High Resolution ◽  
Layer Structure ◽  
High Sensitivity ◽  
Beam Current ◽  
Electron Beam Current ◽  
Lattice Structures ◽  
Super Lattice ◽  
Different Types ◽  
Backscattered Electron ◽  
Electron Imaging

Backscattered electron (BE) images of GaAs/AlGaAs super lattice structures were observed with an ultra high resolution (UHR) SEM JSM-890 with an ultra high sensitivity BE detector. Three different types of super lattice structures of GaAs/AlGaAs were examined. Each GaAs/AlGaAs wafer was cleaved by a razor after it was heated for approximately 1 minute and its crosssectional plane was observed.First, a multi-layer structure of GaAs (100nm)/AlGaAs (lOOnm) where A1 content was successively changed from 0.4 to 0.03 was observed. Figures 1 (a) and (b) are BE images taken at an accelerating voltage of 15kV with an electron beam current of 20pA. Figure 1 (c) is a sketch of this multi-layer structure corresponding to the BE images. The various layers are clearly observed. The differences in A1 content between A1 0.35 Ga 0.65 As, A1 0.4 Ga 0.6 As, and A1 0.31 Ga 0.69 As were clearly observed in the contrast of the BE image.

The Contribution of Intermediate-Voltage, High-Resolution Electron Microscopy In Materials Science: An Appraisal

1990 ◽  
Vol 48 (1) ◽  
pp. 478-479
Author(s):  
John L. Hutchison
Keyword(s):  
High Resolution ◽  
Materials Science ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
The Past ◽  
Resolution Electron ◽  
Extreme Sensitivity ◽  
Electron Microscopes ◽  
New Generation ◽  
Small Metal Particles

Over the past five years or so the development of a new generation of high resolution electron microscopes operating routinely in the 300-400 kilovolt range has produced a dramatic increase in resolution, to around 1.6 Å for “structure resolution” and approaching 1.2 Å for information limits. With a large number of such instruments now in operation it is timely to assess their impact in the various areas of materials science where they are now being used. Are they falling short of the early expectations? Generally, the manufacturers’ claims regarding resolution are being met, but one unexpected factor which has emerged is the extreme sensitivity of these instruments to both floor-borne and acoustic vibrations. Successful measures to counteract these disturbances may require the use of special anti-vibration blocks, or even simple oil-filled dampers together with springs, with heavy curtaining around the microscope room to reduce noise levels. In assessing performance levels, optical diffraction analysis is becoming the accepted method, with rotational averaging useful for obtaining a good measure of information limits. It is worth noting here that microscope alignment becomes very critical for the highest resolution.In attempting an appraisal of the contributions of intermediate voltage HREMs to materials science we will outline a few of the areas where they are most widely used. These include semiconductors, oxides, and small metal particles, in addition to metals and minerals.

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