The Mystery of How Quasicrystals Form

"Since their discovery in 1982, exotic materials known as quasicrystals have bedeviled physicists and chemists. Their atoms arrange themselves into chains of pentagons, decagons, and other shapes to form patterns that never quite repeat. These patterns seem to defy physical laws and intuition. How can atoms possibly "know" how to form elaborate nonrepeating arrangements without an advanced understanding of mathematics?"

"Recently, though, a spate of results has peeled back some of their secrets. In one study, Sun and collaborators adapted a method for studying crystals to determine that at least some quasicrystals are thermodynamically stable-their atoms won't settle into a lower-energy arrangement. This finding helps explain how and why quasicrystals form. A second study has yielded a new way to engineer quasicrystals and observe them in the process of forming."

"Historically, quasicrystals have been challenging to create and characterize. "There's no doubt that they have interesting properties," said Sharon Glotzer, a computational physicist who is also based at the University of Michigan but was not involved with this work. "But being able to make them in bulk, to scale them up, at an industrial level-[that] hasn't felt possible, but I think that this will start to show us how to do it reproducibly.""

Quasicrystals exhibit nonrepeating, quasiperiodic atomic arrangements such as pentagons and decagons that challenged intuition since their 1982 discovery. Recent experimental and computational results reveal that some quasicrystals are thermodynamically stable, meaning their atoms do not relax into lower-energy periodic arrangements. New experimental techniques enable engineering quasicrystals and observing their formation in real time. Additional measurements have uncovered previously unknown physical properties. Historically, manufacturing quasicrystals in bulk and scaling them for industrial use proved difficult. These advances provide mechanisms for reproducible synthesis and clearer understanding of why nonperiodic ordering emerges in solid materials.

Read at WIRED