I am trying to measure the particle size from the coordination number obtained from EXAFS analysis of the sample. Generally, relationship between the coordination number and particle size is given in many publications. But, I am unable to get how to apply these relations to my samples.
The paper linked below (and references therein) might help answer your question. Using EXAFS, particle size and shape are determined by analyzing the coordination numbers in one or more coordination shells. Such methods are routinely used to characterize nanoparticles of face-centered cubic metals such as Pt because of the high degree of symmetry. However, for materials of lower symmetry, this method might be very hard to implement.
Good luck!
http://pubs.rsc.org/en/Content/ArticleLanding/1999/CP/a904654b#!divAbstract
The work by Frenkel et al deals with particle size and shape determination from EXAFS. For sperical particles it is quite simple. you can follow the added link.
http://www.annualreviews.org/doi/full/10.1146/annurev-anchem-061010-113906?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub%3Dpubmed&
The question is interesting but the answer is complex. Coordination numbers are highly correlated with disorder parameters (like Debye Waller like factors when applicable) and may be affected by large systematic/statistical errors. Any precise assessment of particle size should be done combining several measurements (electron microscopy first, XRD). Anyway, EXAFS is really sensitive and the ratio between the amplitude of the signals of the various shells (including multiple-scattering effects!) is a valuable tool. There is a number of high-quality papers, among them I suggest reading that of A. Witkowska (for example A. Witkowska et al. "Local ordering of nano-structured Pt probed by multiple-scattering XAFS", Phys. Rev. B 76, 104110 (2007) (link http://dx.doi.org/10.1103/PhysRevB.76.104110).
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Inorganic Materials
- Metals
- Alloys
- Steel