Nanoparticle superlattice with a C14 Frank-Kasper structure formed by highly monodisperse one-size gold nanoparticles in suspension.

Synthesizing nanoparticle superlattices (NPSLs) with different symmetries is of great interest due to their impact on the collective emergent properties and potential applications. While several parameters have been identified as determinants for forming different symmetries of NPSLs, the high core dispersity, softness, and ligand interpenetration were proposed to drive the formation of the C14 Frank-Kasper (C14) structure like MgZn-type. Here, we report that the C14 phase can be formed in highly monodisperse one-size spherical nanoparticles (NPs) by controlling the interplay among their softness and ligand grafting density.