Researchers used truncated octahedron–shaped silver nanoparticles, or mecons, whose shape and surface chemistry were tuned to promote self-assembly into nanoparticle superlattices that realize the transitional structures along the Nishiyama-Wassermann pathway.

Brown University and the University of Michigan scientists stabilized a transient intermediate structural phase that had been predicted but not previously observed physically.

They demonstrated stabilization of a fleeting intermediate phase between face-centered cubic and body-centered cubic arrangements using specially shaped silver nanoparticles.

A comprehensive supplementary materials package accompanies the article, with extensive figures, tables, and methodological details to reproduce or extend the experiments.

Key collaborators include Ou Chen and Yasutaka Nagaoka of Brown, Tim Moore of Michigan, with theoretical and computational support from Glotzer’s lab at Michigan.

The research was published in Science and supported by multiple NSF grants and Department of Energy funding.

The work reflects a multidisciplinary collaboration across chemistry, physics, and materials science, under funding from the NSF and DOE.

Computational modeling from Sharon Glotzer’s group supported the experiments, showing ligand-coated mecons naturally form configurations consistent with in-transition Nishiyama-Wassermann phases.

Observations and simulations show that sticky ligands are essential for assembling into configurations matching the Nishiyama-Wassermann transition pathways between FCC and BCC.

The team demonstrated that sticky, polymer-coated particles stabilize the transient Nishiyama-Wassermann states at measurable conditions.

The resulting superlattices exhibit high structural purity and stability, enabling direct study of transition pathways between high-symmetry lattices.

The nanoparticle superlattices exhibit deep-strong light-matter coupling and room-temperature quantum optical phenomena, with electrons in silver vibrating in unison with light and showing potential for practical quantum devices.