Insight into the structure of decagonite - the extraterrestrial decagonal quasicrystal

Ireneusz Buganski; Luca Bindi

doi:10.1107/S2052252520015444

Insight into the structure of decagonite - the extraterrestrial decagonal quasicrystal

IUCrJ. 2021 Jan 1;8(Pt 1):87-101. doi: 10.1107/S2052252520015444.

Authors

Ireneusz Buganski^{1

2}, Luca Bindi³

Affiliations

¹ Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krakow, Poland.
² Graduate School of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan.
³ Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Via La Pira 4, Firenze I-50121, Italy.

Abstract

A set of X-ray data collected on a fragment of decagonite, Al₇₁Ni₂₄Fe₅, the only known natural decagonal quasicrystal found in a meteorite formed at the beginning of the Solar System, allowed us to determine the first structural model for a natural quasicrystal. It is a two-layer structure with decagonal columnar clusters arranged according to the pentagonal Penrose tiling. The structural model showed peculiarities and slight differences with respect to those obtained for other synthetic decagonal quasicrystals. Interestingly, decagonite is found to exhibit low linear phason strain and a high degree of perfection despite the fact it was formed under conditions very far from those used in the laboratory.

Keywords: X-ray diffraction; atomic structure refinement; decagonal quasicrystals.

Grants and funding

This work was funded by MIUR-PRIN2017, project ‘TEOREM - deciphering geological processes using terrestrial and extraterrestrial ORE minerals’, prot. 2017AK8C32 (PI: Luca Bindi) grant 2017AK8C32. Polish National Science Centre grant 2019/33/B/ST3/02063.