A New Wavelength-Based Model for Subtracting Instrumental Broadening in Nanocrystallite Size Determination by XRD

Nanocrystallite size determination by X-ray diffraction (XRD) is one of the most important characterizations for nanomaterials. The biggest error in determination is considered instrumental broadening (IB), which often needs to be subtracted according to peak profile analysis. However, it is neither direct nor accurate enough to distinguish peak profile ascription, and it is also not convenient to be employed in the industry. To address this challenge, this paper developed a new mathematical model based on a multi-wavelength experiment, which could individually analyze each peak and sequentially subtract IB. To verify the validity and accuracy, Si nanopowder was tested and the crystallite size was determined, in which instrument broadening was subtracted by the new model and the current methods. A new model was suggested as the most precise one because the effect of instrumental broadening on the peak profile was sufficiently considered.