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A Preliminary Report of the Design and Results of the Second Round Robin to Evaluate Search/Match Methods for Qualitative Powder Diffractometry*

Published online by Cambridge University Press:  06 March 2019

Ron Jenkins
Affiliation:
Philips Electronic Instruments, Inc., Mahwah, NJ National Bureau of Standards, Washington, D. C. 20234
Camden R. Hubbard
Affiliation:
Philips Electronic Instruments, Inc., Mahwah, NJ National Bureau of Standards, Washington, D. C. 20234
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Abstract

Six computer synthesized data sets, each representing a mixture, and one physical mixture were prepared and widely distributed in order to study the various search/match methods and factors which affect their success. A total of 67 returns were received representing eight countries and three search methods. The participants were primarily from industrial laboratories. The average score exceeded 90%. The Hanawalt search method yielded the best overall score. Use of the Frequently Encountered Phases subfile decreased the search time by about 40% and marginally increased the success rate. For the physical mixture the Δd/d and ΔI/I values were measured to about 2/1000 and 40% respectively. Use of an internal standard improved the d-values by a factor of 2 and resulted in better search/match performance.

Type
Research Article
Copyright
Copyright © International Centre for Diffraction Data 1978

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Footnotes

**

Chairman, Computer Subcommittee, JCPDS-International Centre for Diffraction Data

Chairman, Education Subcommittee, JCPDS-International Centre for Diffraction Data

*

Contribution of the National Bureau of Standards. Not Subject to copyright

References

1. Jenkins, R., “A Round Robin Test To Evaluate Computer Search/ Match Methods for Qualitative Powder Diffractometry,” Adv. X-Ray Anal., 20 (1977) p 125137.Google Scholar
2. JCPDS-International Centre for Diffraction Data, 1601 Park Lane, Swarthmore, PA 190 81 U.S.A.Google Scholar
3. The Si (SRM-640) was kindly supplied by the Office of Standard Reference Materials, National Bureau of Standards, Washington, D.C. 20234 U.S.A.Google Scholar