Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-11T07:03:28.623Z Has data issue: false hasContentIssue false
  • English
  • Français

Manual Search/Match Methods for Powder Diffraction in 1986

Published online by Cambridge University Press:  10 January 2013

J. D. Hanawalt
J. D. Hanawalt
Affiliation:
The University of Michigan
Get access Rights & Permissions [Opens in a new window]

Extract

The objectives of this paper are: 1. to up-date the manual search system and index book described in 1936 and 1938; 2. to introduce a “work form” which serves to guide the analyst through the procedural steps involved in using the manual search index book and 3. to review briefly the literature on manual search/match systems.

Two of the basic features of the 1936 design of the search index book were first, to divide the “d” range into arbitrarily sized “groups” and “subgroups” rather than using a scale of continuously decreasing “d” values, and second, to use the “d” values of the strongest lines of the diffraction pattern in order of decreasing intensity in making the entries of the standard patterns in the search index book. These two features are still the basis of the design of the 1986 Hanawalt Search Manual published by the JCPD S International Centre for Diffraction Data.

The original use of the search index book at Dow Chemical was to lead the analyst to corresponding patterns among the thousands of Debye films which had been produced and placed on file. The “d” values and intensities of only the three or four strongest lines of the pattern were measured. Comparisons and indentifications were then made visually simply by holding the concerned films together in juxtaposition. Unfortunately, attempts to reproduce usable copies of such Debye films for general reference have not been satisfactory. Therefore, for general usage the diffraction data carried by the film negative or also the data from a diffractometer trace are recorded using the numerical values of the “d” spacings and intensities. These tables of numerical data are then used to represent the diffraction patterns. The search index book for general usage must therefore deal entirely with these numerical values.

Type
Research Article
Information
Powder Diffraction , Volume 1 , Issue 1 , March 1986 , pp. 7 - 13
Copyright
Copyright © Cambridge University Press 1986

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.)

References

1.Debye, P. and Scherrer, P., Phys. Z. 17, 277 (1916); 18, 291 (1917)Google Scholar
2.Hull, A. W., Phys. Rev. 10, 661 (1917);Google Scholar
J. Am. Chem. Soc. 41, 1169, (1919)Google Scholar
3.Winchell, A. N., Am. Min. 12, 261 (1927)Google Scholar
4.Waldo, A. W., Am. Min. 20, 575 (1935)Google Scholar
5.Hanawalt, J. D. and Rinn, H. W., Ind. Eng. Chem., Anal. Ed. 8, 244 (1936)CrossRefGoogle Scholar
6.Hanawalt, J. D., Rinn, H. W. and Frevel, L. K., Ind. Eng. Chem., Anal. Ed. 10, 457 (1938)CrossRefGoogle Scholar
7.Boldyrev, A. K., Mikheev, V. I., Dubinina, V. N. and Dovalev, G. A., Ann. Inst. Mines Leningrad 11, 1 (1938)Google Scholar
8.Frevel, L. K., Anal. Chem. 37, 471 (1965)Google Scholar
9.Bigelow, W. C. and Smith, J. V., ASTM, S.T.P. 372, 54 (1965)Google Scholar
10.Hanawalt, J. D., Advances in X-ray Analysis, 20, 63 (1976)CrossRefGoogle Scholar
11.Messick, Julian, JCPDS-International Centre for Diffraction Data (1974)Google Scholar
12.Sturman, B. D., JCPDS-International Centre for Diffraction Data (1976)Google Scholar