Conclusive verification of Pt core segregation in CuPdAgPtAu HEA nanoparticles

Determine whether platinum segregates toward the core of CuPdAgPtAu high-entropy alloy nanoparticles synthesized by laser ablation in liquids (in acetone), as predicted by atomistic simulations, using characterization methods capable of resolving surface versus core distributions.

Background

Atomistic Monte Carlo and molecular dynamics simulations in this study predict that platinum should preferentially occupy the core region of CuPdAgPtAu nanoparticles due to its higher surface energy, whereas silver should enrich at the surface. Experimental XPS data provide indirect support for Pt core enrichment, while STEM-EDS elemental mapping did not reveal clear Pt segregation.

Because elemental mapping lacked conclusive evidence for Pt diffusion to the core and XPS is surface-sensitive with limited depth resolution, the authors highlight that the presence of Pt core segregation remains to be conclusively established. They suggest that additional methods, such as focused ion beam cross-sectioning, could help resolve the radial distribution of elements.