Scientists from the IQFR and the University of Oxford published in Nature how to make icosahedral quasicrystals using particles with directional bonding
Aperiodic crystals, briefly called quasicrystals, are ordered structures but they are not periodic, that is, they cannot be obtained by replicating a structural unit (the unit cell in crystals) in the three dimensions of space. Dan Shechtman observed the first icosahedral quasicrystal in 1982, while measuring the diffraction patterns formed when beams of electrons passed through various metal alloys obtained by rapid quench of the melt. He observed that one of these alloys produced a diffraction pattern that exhibited six five-fold axes, like an icosahedron, challenging the basic principles of crystallography and leading to a paradigm shift in this discipline.
Since then, numerous icosahedral quasicrystals have been produced from binary and ternary metallic alloys, and even some natural quasicrystals have been found in meteorites. But they have never been observed in covalent materials where the bonds are directional. In a work published in Nature, scientist from the IQFR and the University of Oxford show that it is possible to produce icosahedral quasicrystals by directional bonds if ones is not limited to the geometric possibilities available in atomic systems.
The authors argue that these types of materials could be built in the laboratory using colloidal or DNA origami particles, where both the geometry of the particles and the way they interact with each other can be controlled with current technology. If the constituent nanoparticles have the appropriate size, materials can be achieved that inhibit the propagation of light at certain frequencies in all directions, which makes them especially attractive in various applications in photonics (sensors , optical chips, telecommunications devices, ...)
How to design an icosahedral quasicrystal through directional bonding, Eva G. Noya, Chak Kui Wong, Pablo Llombart and Jonathan P.K. Doye, Nature 596, 367-371 (2021). https://doi.org/10.1038/s41586-021-03700-2
The story of how this project was born can be found in the blog Behind the Paper https://go.nature.com/3dlKL0V
