I calculated the crystallite size of a nanopowder by the Scherrer method from the XRD data of a powder diffractometer? How to determine the error of the Scherrer method and what this error is generated?
R. M. Emirov
The main error is that Scherrer deals with all line broadening and not just size - so there are strain and instrumental factors to take into account. Williamson-Hall may be a better bet to separate these out. Did you use the Warren correction?
Several factors to bear in mind:
- The is a crystallite size distribution and Scherrer only produces a single value
- The main experimental difficulty (try manual analysis on a raw film, as I did, and you'll see) is defining the extent of broadening - it's a judgement call for small crystallites (which may require longer x-ray exposure times too) where the peaks are quite diffuse. For larger sizes then the broadening can be too small to judge correctly
- The value of the constant (~ 0.9) is irrelevant , IMHO. It just needs to be quoted in any stated calculation and others can amend as appropriate
- Each line in the diffractogram you select will give you a different estimate of the crystallite size. Will you use a (111) or (100) peak and why?
- Errors in defining the wavelength of irradiation (Cu Kalpha?) are irrelevant when compared against the value (assumed) of the Scherrer constant
- Scherrer is spelled thus and you can correct the (minor) typo in your question with the downward arrow key
Alan F Rawle
Thanks for your reply! No, I'm not using the Warren Amendment. If we calculate the AVERAGE crystallite size by the Scherrer method, is the error of this method important?
May be the study given at link help to rectify this issue; https://www.researchgate.net/publication/352830671or http://dx.doi.org/10.13140/RG.2.2.27720.65287.
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