Uncertainty evaluation of crystallite size measurements of nanoparticle using X-Ray diffraction analysis (XRD)

Abstract

Crystallite size is one of the critical powder characteristics to determine nano-scale properties used in many industrial applications. The crystallite size can be extracted by X-ray Diffraction (XRD) analysis since it is one of the simplest and the most convenient method among numerous characterization techniques. However, the lack of suitable uncertainty evaluation for determining crystallite size makes the measurement questionable. Therefore, this paper has presented the uncertainty evaluation for crystallite size measurement based on the method of JCGM 100:2008. The main contributions according to the Scherrer equation consist of the Scherrer constant (K), the X-ray wave length (λ), the full width of the peak at half maximum intensity (FWHM), the diffraction angle (θ), and also the resolution and repeatability effect. The measurement process, statement of the standard uncertainty of the component sources, sensitivity coefficient and the combined standard uncertainty of crystallite size measurement have been explained in detail. A numerical example presents how to estimate the uncertainty budget for the nanoparticle of TiO2 or P25 which is a commercially available powder.