Comparison of methods for determining mean size of polydispersed nanoparticles
Abstract
Samples of platinum nanoparticles exhibiting moderate polydispersion were studied by three methods: x-ray diffraction (XRD), extended x-ray absorption fine structure (EXAFS), and high resolution transmission electron microscopy (HRTEM). While HRTEM yielded a size distribution for each sample, XRD (using Scherrer analysis), and EXAFS (using a homogenous spherical model) were used to determine a "mean" particle size. Since XRD is weighted by the square of the volume and EXAFS by less than the volume, XRD is expected to generally yield a larger mean value than EXAFS. In this study, the HRTEM distributions were used as the basis for theoretical simulations that calculated the mean sizes as weighted by both the XRD and EXAFS methods. Finally, these calculations were compared with the results of actual XRD and EXAFS experiments. In this way, the relative merits of XRD and EXAFS for providing estimates of particle size were evaluated.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARH14009L