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Identification of Multiphase Unknowns by Computer Methods: Role of Chemical Information, the Quality of X-Ray Powder Data and Subfiles

Published online by Cambridge University Press:  06 March 2019

Gregory J. McCarthy  and
Gerald G. Johnson Jr.
Gregory J. McCarthy
Affiliation:
Materials Research Laboratory, The Pennsylvania State University, University Park, PA 16802
Gerald G. Johnson Jr.
Affiliation:
Materials Research Laboratory, The Pennsylvania State University, University Park, PA 16802
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Abstract

Three variables in the identification of crystalline multiphase unknowns by computer search/match methods were examined: presence or absence of chemical information; varying quality of d-I diffraction data; use of a large data base vs a data base having about 10% as many entries--both contain the unknown phases. The results showed that the search/match using average quality d-I data with chemical information was quite successful, while that obtained using higher quality d-I data alone missed one of four phases. It took only half the time to obtain the average d-I data plus chemistry as it did to obtain the higher quality data. Searching the smaller data base with the higher quality data alone resulted in an identification of all phases with high reliability.

Type
Research Article
Information
Advances in X-Ray Analysis , Volume 22: Twenty-Seventh Annual Conference on Applications of X-ray Analysis, August 1-4, 1978 , 1978 , pp. 109 - 120
Copyright
Copyright © International Centre for Diffraction Data 1978

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References

1. McClune, W. F., Managing Editor, Powder Diffraction File, JCPDS, International Center for Diffraction Data, Swarthmore, PA.Google Scholar
2. The “Diffraction Data Tele Search (2 DTS),” JCPDS, International Center for Diffraction Data, Swarthmore, PA.Google Scholar
3. Hubbard, C. R. and Jenkins, R., “Design and Preliminary Results of the Second Round Robin to Evaluate Search/Match Methods for Quantitative Powder Diffractometry” (Abstract), 26th Annual Conference on Applications of X-ray Analysis, Denver, CO, p. 42, August 1977.Google Scholar
4. Hubbard, C. R. and Jenkins, R., “Design and Results of the Second Round Robin to Evaluate Search/Match Methods for Quantitative Powder Diffractometry,” this volume.Google Scholar
5. Johnson, G. G. Jr., “Resolution of X-ray Powder Patterns,” in Mattson, J. S., Mark, H. B. Jr., and H. C. MacDonald, Jr. (Eds.), Laboratory Systems and Spectroscopy, Chapter 3 (1977).Google Scholar
6. Johnson, G. G. Jr., “User Guide. Data Base and Search Manual,” Publ. by JCPDS, International Center for Diffraction Data, Swarthmore, PA (available on request).Google Scholar
7. Dismore, P. F., “Computer Searching of the JCPDS Powder Diffraction File,” Adv. in X-ray Analysis, Vol. 20, McMurdie, H. F., et al., Eds., Plenum Press, New York (1977).Google Scholar