Development of nanoparticle bulk morphology analysis: a multidomain XRD approach

Area of Science:

• Materials Science
• Nanotechnology
• Crystallography

Background:

• Twin and stacking faults in nanoparticles introduce strain, impacting catalytic, optical, and electrical properties.
• Current experimental methods lack quantitative characterization of these defects, hindering structure-property correlation understanding.

Purpose of the Study:

• To explore the effect of twinning on X-ray diffraction (XRD) patterns.
• To develop a practical, quantitative method for characterizing twin faults in nanomaterials.
• To establish structure-property correlations in nanoparticle studies.

Main Methods:

• Computational simulations to investigate the relationship between domain orientation and XRD peak ratios.
• Development of a new XRD approach based on the mutual orientation of face-centered cubic (fcc) segments.
• Experimental XRD analysis of gold (Au) and gold-platinum (AuPt) nanoparticles.
• Comparison of XRD results with Transmission Electron Microscopy (TEM) and Small-Angle X-ray Scattering (SAXS) data.

Main Results:

• A correlation was identified: an increased number of domains leads to a decreased height ratio of 220 to 111 diffraction peaks.
• The developed XRD method successfully analyzed the bulk morphology and size of Au and AuPt samples.
• Results from the new XRD method showed good agreement with TEM and SAXS analyses.

Conclusions:

• The study presents a novel, computationally-guided XRD method for quantifying twin faults in nanoparticles.
• This multidomain XRD approach offers a simple and effective alternative to TEM for defect characterization.
• The method facilitates a better understanding of structure-property relationships in nanomaterials.