Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-26T21:08:40.735Z Has data issue: false hasContentIssue false

Computer Search/Match of Standards Containing a Small Number of Reflections

Published online by Cambridge University Press:  06 March 2019

T. C. Huang
Affiliation:
IBM Research Laboratory, San Jose, California 95193
W. Parrish
Affiliation:
IBM Research Laboratory, San Jose, California 95193
B. Post
Affiliation:
Polytechnic Institute of New York, Brooklyn, NY 11201
Get access

Abstract

A simplified and effective computer Search/Match method is described in which no more than 12 largest d-value reflections regardless of intensities are used for the Powder Diffraction File standards. A quantitative procedure utilizing the figure-of-merit in the IBM Search/Match method was employed to show the applicability to inorganic, mineral and organic mixtures. The analyses gave the same results as the complete File but the standard databases and analysis time are reduced by about a factor of two. Search/Match without using intensities also gave the same results; this may be useful when instrument geometry and/or preferred orientation cause large errors in the relative intensities. The error limits in measuring the d-spacings were found to vary from ±0.1° to 0.5° (26) depending on the degree of overlaps.

Type
II. Search/Match Procedures, Powder Diffraction File
Copyright
Copyright © International Centre for Diffraction Data 1982

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

Part of this work was presented at the ACA meeting, NBS, March 1982.

References

(1) JCPDS-International Centre for Diffraction Data, 1601 Park Lane, Swarthmore, Pennsylvania 19081.Google Scholar
(2) Nichols, M. C., Minicomputer Search/Match; The Pros and Cons, Norelco Reporter 27:23 (1980),Google Scholar
(3) Hare, T. M., Russ, J. C., and Lanzo, M. J., X-Ray Diffraction Phase Analysis Using Microcomputers, Adv. X-Ray Anal. 25237 (1982).Google Scholar
(4) Huang, T. C. and Parrish, W., A Mew Computer Algorithm for Qualitative X-Ray Powder Diffraction Analysis, Adv. X-Ray Anal. 25:213 (1982).Google Scholar
(5) Johnson, G. G., Jr., “User Guide:Data Base and Search Program,” JCPDS, Swarthmore, PA (1975).Google Scholar
(6) Parrish, W., Ayers, G. L. and Huang, T. C., A Versatile Minicomputer X-Ray Search/Match System, Adv. X-Ray Anal. 25:221 (1982).Google Scholar
(7) Jenkins, R. and Hubbard, C. R., A preliminary Report on the Design and Results of the Second Round Robin to Evaluate Search/Match Methods for Qualitative Powder Diffractometry, Adv. X-Ray Anal. 22;133 (1979).Google Scholar
(8) Jenkins, R., A Round Robin Test to Evaluate Computer Search/Match Methods for Qualitative Powder Diffractometry, Adv. X-Ray Anal. 20;125 (1977).Google Scholar