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Automatic Computer Measurement of Selected Area Electron Diffraction Patterns from Asbestos Minerals

Published online by Cambridge University Press:  06 March 2019

J. C. Russ
Affiliation:
Materials Sci. & Eng. Dept., North Car. State Univ., Raleigh, NC
T. Taguchi
Affiliation:
Hitachi Scientific Instruments, Rockville, MD
P. M. Peters
Affiliation:
Div. Industrial Safety & Health, State of Wash., Olympia, WA
E. Chatfield
Affiliation:
Chatfield Technical Consulting, Mississauga, Ontario, Canada
J. C. Russ
Affiliation:
Biomedical Engineering Dept., University of Texas, Austin, TX
W. D. Stewart
Affiliation:
Dapple Systems, Sunnyvale, CA
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Conventional selected area diffraction patterns as obtained in the TEM present difficulties for identification of materials such as asbestifonn minerals, although diffraction data is considered to be one of the preferred methods for making this identification. The preferred orientation of the fibers in each field of measurement, and the spotty patterns that are obtained, do not readily lend themselves to measurement of the integrated intensity values for each dspacing, and even the d-spacings may be hard to determine precisely because the true center location for the broken rings requires estimation. To overcome these problems, we have implemented an automatic method for diffraction pattern measurement. It automatically locates the center of patterns with high precision, measures the radius of each ring of spots in the pattern, and integrates the density of spots in that ring.

Type
IX. Qualitative and Quantitative Phase Analysis Diffraction Applications
Copyright
Copyright © International Centre for Diffraction Data 1988

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References

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