Development of nanoparticle bulk morphology analysis: a multidomain XRD approach

The appearance of twin/stacking faults in nanoparticles creates strains affecting the catalytic, optical, and electrical properties of nanomaterials. Currently, there is a lack of experimental tools for a numeric characterization of these defects in samples. Therefore, many structure-property correlations are poorly understood. Here, we report the exploration of the twinning effect on the XRD pattern and its practical application. We developed a new approach focused on the special mutual orientation of periodic fcc segments, domains. Using computational simulations, we found that the more domains, the smaller the height ratio of 220 to 111 diffraction peaks. Knowing this correlation, we performed the XRD bulk morphology and size analysis of Au and AuPt samples. The obtained results were compared with the results of TEM and SAXS analyses. In a broader context, our multidomain XRD method is a simple alternative to TEM which enables unraveling the structure-property correlations in NP studies.

Automated summary

The appearance of twin/stacking faults in nanoparticles affects their catalytic, optical, and electrical properties. However, there is a lack of experimental tools for characterizing these defects numerically, leading to poor understanding of structure-property correlations. In this study, we explored the twinning effect on XRD pattern and developed a new approach based on the mutual orientation of periodic fcc segments. By performing computational simulations, we found a correlation between the number of domains and the height ratio of 220 to 111 diffraction peaks. Our XRD analysis of Au and AuPt samples, compared with TEM and SAXS analyses, demonstrates the potential of our multidomain XRD method in studying structure-property correlations in nanomaterials.