Materials adopting the diamond structure possess useful properties in atomic and colloidal systems, and are a popular target for synthesis in colloids where a photonic band gap is possible. The desirable photonic properties of the diamond structure pose an interesting opportunity for reconfigurable matter: can we create a colloidal crystal able to switch reversibly to and from the diamond structure? Drawing inspiration from high-pressure transitions of diamond-forming atomic systems, we design a system of polyhedrally-shaped particles that transitions from diamond to a tetragonal diamond derivative upon a small pressure change. The transition can alternatively be triggered by changing the shape of the particle in-situ. We propose that the transition provides a reversible reconfiguration process for a potential new colloidal material, and draw parallels between this transition and phase behavior of the atomic transitions from which we take inspiration.
@article{arxiv.1803.06388,
title = {Pressure-Tunable Photonic Band Gaps in an Entropic Colloidal Crystal},
author = {Rose K. Cersonsky and Julia Dshemuchadse and James A. Antonaglia and Greg van Anders and Sharon C. Glotzer},
journal= {arXiv preprint arXiv:1803.06388},
year = {2018}
}