An evaluation of deconvolution techniques in x-ray profile broadening analysis and the application of the maximum entropy method to alumina data
- Univ. of Technology, Sydney (Australia)
- National Inst. of Standards and Technology Gaithersburg, MD (United States)
This paper reviews several procedures for the removal of instrumental contributions from measured x-ray diffraction profiles, including: direct convolution, unconstrained and constrained deconvolution, an iterative technique, and a maximum entropy method (MEM) which we have adapted to x-ray diffraction profile analysis. Deconvolutions using the maximum entropy approach were found to be the most robust with simulated profiles which included Poisson-distributed noise and uncertainties in the instrument profile function (IPF). The MEM procedure is illustrated by application to the analysis for domain size and microstrain carried out on the four calcined {alpha}-alumina candidate materials for Standard Reference Material (SRM) 676 (a quantitative analysis standard for I/I{sub c} determinations), along with the certified material. Williamson-Hall plots of these data were problematic with respect to interpretation of the microstrain, indicating that the line profile standard, SRM 660 (LaB{sub 6}), exhibits a small amount of strain broadening, particularly at high 2{theta} angle. The domain sizes for all but one of the test materials were much smaller than the crystallite (particle) size; indicating the presence of low angle grain boundaries. 19 refs., 3 figs., 1 tab.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 369836
- Report Number(s):
- CONF-9408178-; ISSN 0376-0308; TRN: 96:004756-0039
- Journal Information:
- Advances in X-Ray Analysis, Vol. 38; Conference: 43. annual Denver x-ray conference on applications of x-ray analysis, Steamboat Spring, CO (United States), 1-5 Aug 1994; Other Information: PBD: 1995
- Country of Publication:
- United States
- Language:
- English
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