Nanoparticle size distribution from inversion of wide angle X-ray total scattering data

Area of Science:

• Nanoscience and Nanotechnology
• Materials Science
• Crystallography

Background:

• Accurate nanoparticle sizing is essential in nanoscience and nanotechnology.
• Wide-angle X-ray total scattering (WAXTS) is a key technique for determining particle size distributions (PSDs).
• Current methods often require prior assumptions about PSD shape, limiting accuracy.

Purpose of the Study:

• To develop a robust method for accurate PSD determination from WAXTS data.
• To overcome the limitations of a-priori assumptions on PSD shape.
• To demonstrate the algorithm's effectiveness on real and simulated nanocrystal samples.

Main Methods:

• Modification of the iterative Lucy-Richardson (LR) algorithm for WAXTS data inversion.
• Computer simulations using the Debye Scattering Equation (DSE) to model WAXTS data.
• Application and validation of the algorithm on Magnetite-Maghemite and P25-Titania nanopowders.

Main Results:

• The modified LR algorithm accurately recovers PSDs regardless of their shape, even with noise.
• Simulations show reliable PSD recovery for mixed polymorphs and samples with microstrain.
• Accurate nanoparticle crystal structure modeling is crucial for robust PSD inversion.

Conclusions:

• The proposed LR algorithm provides a reliable and shape-independent method for PSD determination from WAXTS data.
• This approach enhances the accuracy of nanoparticle characterization, especially for polydisperse samples.
• Accurate structural information is vital for successful WAXTS data inversion and PSD recovery.