Application of XRD diffraction methods for determination of grain size distribution in nanoparticles
|Roman Pielaszek , Witold Łojkowski|
Polish Academy of Sciences, Institute of High Pressure Physics (UNIPRESS), Sokolowska 29/37, Warszawa 01-142, Poland
During XRD measurement, X-ray detectors (counters) register scattered photons with a finite efficiency. This results in experimental noise proportional to the square root of the intensity, according to well known properties of Bernoulli distribution.
In standard cases signal/noise ratio suffices for X-Ray phase analysis (determination of crystalline phases) and basic grain size approximation by measurement of peak width. However, further investigations of a fine structure of the peak profile may be affected by high noise amplitude.
In the present paper we discuss determination of the size distribution of nanocrystals by analysis of the fine structure of the peak profile. Influence of the experimental noise and resulting accuracy of the method will be investigated. We will estimate photon flux (X-ray tube/synchrotron) needed for successful evaluation and give a practical directions on optimal experimental setup. Dispersion of the size distribution parameters (i.e. dispesion of average grain size and dispersion of dispersion of the grain sizes) will be given as a function of experimental noise level.
Presentation: invited oral at E-MRS Fall Meeting 2005, Symposium I, by Roman Pielaszek
See On-line Journal of E-MRS Fall Meeting 2005
Submitted: 2005-05-30 20:15 Revised: 2009-06-07 00:44