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1. Accidental synthesis of a previously unknown quasicrystal in the first atomic bomb test

   https://doi.org/10.1073/pnas.2101350118  

   Bindi, Luca; Kolb, William; Eby, G. Nelson; Asimow, Paul D.; Wallace, Terry C.; Steinhardt, Paul J. (May 2021, Proceedings of the National Academy of Sciences)

   The first test explosion of a nuclear bomb, the Trinity test of 16 July 1945, resulted in the fusion of surrounding sand, the test tower, and copper transmission lines into a glassy material known as “trinitite.” Here, we report the discovery, in a sample of red trinitite, of a hitherto unknown composition of icosahedral quasicrystal, Si₆₁Cu₃₀Ca₇Fe₂. It represents the oldest extant anthropogenic quasicrystal currently known, with the distinctive property that its precise time of creation is indelibly etched in history. Like the naturally formed quasicrystals found in the Khatyrka meteorite and experimental shock syntheses of quasicrystals, the anthropogenic quasicrystals in red trinitite demonstrate that transient extreme pressure–temperature conditions are suitable for the synthesis of quasicrystals and for the discovery of new quasicrystal-forming systems. 

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2. Electrical discharge triggers quasicrystal formation in an eolian dune

   https://doi.org/10.1073/pnas.2215484119  

   Bindi, Luca; Pasek, Matthew A.; Ma, Chi; Hu, Jinping; Cheng, Guangming; Yao, Nan; Asimow, Paul D.; Steinhardt, Paul J. (January 2023, Proceedings of the National Academy of Sciences)

   We report the discovery of a dodecagonal quasicrystal Mn 72.3 Si 15.6 Cr 9.7 Al 1.8 Ni 0.6 —composed of a periodic stacking of atomic planes with quasiperiodic translational order and 12-fold symmetry along the two directions perpendicular to the planes—accidentally formed by an electrical discharge event in an eolian dune in the Sand Hills near Hyannis, Nebraska, United States. The quasicrystal, coexisting with a cubic crystalline phase with composition Mn 68.9 Si 19.9 Ni 7.6 Cr 2.2 Al 1.4 , was found in a fulgurite consisting predominantly of fused and melted sand along with traces of melted conductor metal from a nearby downed power line. The fulgurite may have been created by a lightning strike that combined sand with material from downed power line or from electrical discharges from the downed power line alone. Extreme temperatures of at least 1,710 °C were reached, as indicated by the presence of SiO 2 glass in the sample. The dodecagonal quasicrystal is an example of a quasicrystal of any kind formed by electrical discharge, suggesting other places to search for quasicrystals on Earth or in space and for synthesizing them in the laboratory. 

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3. Metallic messengers from the cosmos: Rare (Al,Cu)‐bearing meteorites from the Project Stardust collection

   https://doi.org/10.1111/maps.14377  

   Bindi, Luca; Larsen, Jon; Kihle, Jan B; Cheng, Guangming; Hu, Jinping; Yao, Nan; Ma, Chi; Guan, Yunbin; Asimow, Paul D; Steinhardt, Paul J (July 2025, Meteoritics & Planetary Science)

   Abstract We report the discovery of (Al,Cu)‐bearing metallic alloys in two micrometeorites found in the Project Stardust collection gathered from urban rooftop environments in Norway. Most of the alloys are the same as those found in the Khatyrka meteorite and other micrometeorites, though one has a composition that has not been reported previously. Oxygen isotope ratio measurements using secondary ion mass spectrometry show that the Project Stardust samples reported here, like all earlier examples of natural (Al,Cu)‐bearing alloys, contain material of chondritic affinity. 

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4. Ultrafast X-ray Diffraction Study of a Shock-Compressed Iron Meteorite above 100 GPa

   https://doi.org/10.3390/min11060567  

   Tecklenburg, Sabrina; Colina-Ruiz, Roberto; Hok, Sovanndara; Bolme, Cynthia; Galtier, Eric; Granados, Eduardo; Hashim, Akel; Lee, Hae Ja; Merkel, Sébastien; Morrow, Benjamin; et al (June 2021, Minerals)

   null (Ed.)

   Natural kamacite samples (Fe92.5Ni7.5) from a fragment of the Gibeon meteorite were studied as a proxy material for terrestrial cores to examine phase transition kinetics under shock compression for a range of different pressures up to 140 GPa. In situ time-resolved X-ray diffraction (XRD) data were collected of a body-centered cubic (bcc) kamacite section that transforms to the high-pressure hexagonal close-packed (hcp) phase with sub-nanosecond temporal resolution. The coarse-grained crystal of kamacite rapidly transformed to highly oriented crystallites of the hcp phase at maximum compression. The hcp phase persisted for as long as 9.5 ns following shock release. Comparing the c/a ratio with previous static and dynamic work on Fe and Fe-rich Fe-Ni alloys, it was found that some shots exhibit a larger than ideal c/a ratio, up to nearly 1.65. This work represents the first time-resolved laser shock compression structural study of a natural iron meteorite, relevant for understanding the dynamic material properties of metallic planetary bodies during impact events and Earth’s core elasticity. 

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5. Entropic formation of a thermodynamically stable colloidal quasicrystal with negligible phason strain

   https://doi.org/10.1073/pnas.2011799118  

   Je, Kwanghwi; Lee, Sangmin; Teich, Erin G.; Engel, Michael; Glotzer, Sharon C. (February 2021, Proceedings of the National Academy of Sciences)

   null (Ed.)

   Quasicrystals have been discovered in a variety of materials ranging from metals to polymers. Yet, why and how they form is incompletely understood. In situ transmission electron microscopy of alloy quasicrystal formation in metals suggests an error-and-repair mechanism, whereby quasiperiodic crystals grow imperfectly with phason strain present, and only perfect themselves later into a high-quality quasicrystal with negligible phason strain. The growth mechanism has not been investigated for other types of quasicrystals, such as dendrimeric, polymeric, or colloidal quasicrystals. Soft-matter quasicrystals typically result from entropic, rather than energetic, interactions, and are not usually grown (either in laboratories or in silico ) into large-volume quasicrystals. Consequently, it is unknown whether soft-matter quasicrystals form with the high degree of structural quality found in metal alloy quasicrystals. Here, we investigate the entropically driven growth of colloidal dodecagonal quasicrystals (DQCs) via computer simulation of systems of hard tetrahedra, which are simple models for anisotropic colloidal particles that form a quasicrystal. Using a pattern recognition algorithm applied to particle trajectories during DQC growth, we analyze phason strain to follow the evolution of quasiperiodic order. As in alloys, we observe high structural quality; DQCs with low phason strain crystallize directly from the melt and only require minimal further reduction of phason strain. We also observe transformation from a denser approximant to the DQC via continuous phason strain relaxation. Our results demonstrate that soft-matter quasicrystals dominated by entropy can be thermodynamically stable and grown with high structural quality––just like their alloy quasicrystal counterparts. 

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