Structural Analysis of AuPdAu Nanocubes via Aberration-Corrected STEM and Nanobeam Diffraction

Controlling the morphology of bimetallic nanoscale systems at the atomic level is of utmost importance in fields such as nanocatalysis, plasmonics, or optics. In this report we emphasize an experimental observation of superlattice formation in bimetallic gold-palladium nanocubes of the order of 30 nm synthesized by a seed-mediated growth method. By combining our experimental observations based on high-angle annular dark-field scanning transmission electron microscopy and nanobeam diffraction, we have established that a process of galvanic replacement takes place in our third deposition step, triggering the formation of vacancies and atomic diffusion, triggering short-range ordering in our three-layer AuPdAu nanocubes.