Capturing the Transient Phases of Nanocrystal Superlattice via Shape-Controlled Synthesis

Nanocrystal superlattices are ordered arrays of colloidal nanocrystals, often viewed as artificial solids in which nanocrystals replace atoms as the structural units. This article highlights a recent study in which the shape of silver nanocrystals was finely tuned to direct their assembly into superlattices from face-centered cubic to body-centered cubic structures, while accessing the transient intermediate structures along the Nishiyama-Wassermann martensitic pathway. By tuning nanocrystal sphericity and revealing the role of soft ligand-mediated interactions through computational simulation, this work shows how the shape of nanocrystal can be tailored to stabilize an intermediate superlattice phase and modulate its optical response.