A Caltech Library Service

First synthesis of a unique icosahedral phase from the Khatyrka meteorite by shock-recovery experiment

Hu, Jinping and Asimow, Paul D. and Ma, Chi and Bindi, Luca (2020) First synthesis of a unique icosahedral phase from the Khatyrka meteorite by shock-recovery experiment. International Union of Crystallography Journal, 7 (3). pp. 434-444. ISSN 2052-2525. PMCID PMC7201281. doi:10.1107/s2052252520002729.

[img] PDF - Published Version
Creative Commons Attribution.

[img] PDF - Supplemental Material
Creative Commons Attribution.


Use this Persistent URL to link to this item:


Icosahedral quasicrystals (i-phases) in the Al–Cu–Fe system are of great interest because of their perfect quasicrystalline structure and natural occurrences in the Khatyrka meteorite. The natural quasicrystal of composition Al₆₂Cu₃₁Fe₇, referred to as i-phase II, is unique because it deviates significantly from the stability field of i-phase and has not been synthesized in a laboratory setting to date. Synthetic i-phases formed in shock-recovery experiments present a novel strategy for exploring the stability of new quasicrystal compositions and prove the impact origin of natural quasicrystals. In this study, an Al–Cu–W graded density impactor (GDI, originally manufactured as a ramp-generating impactor but here used as a target) disk was shocked to sample a full range of Al/Cu starting ratios in an Fe-bearing 304 stainless-steel target chamber. In a strongly deformed region of the recovered sample, reactions between the GDI and the steel produced an assemblage of co-existing Al_(61.5)Cu_(30.3)Fe_(6.8)Cr_(1.4) i-phase II + stolperite (β, AlCu) + khatyrkite (θ, Al₂Cu), an exact match to the natural i-phase II assemblage in the meteorite. In a second experiment, the continuous interface between the GDI and steel formed another more Fe-rich quinary i-phase (Al_(68.6)Fe_(14.5)Cu_(11.2)Cr₄Ni_(1.8)), together with stolperite and hollisterite (λ, Al₁₃Fe₄), which is the expected assemblage at phase equilibrium. This study is the first laboratory reproduction of i-phase II with its natural assemblage. It suggests that the field of thermodynamically stable icosahedrite (Al₆₃Cu₂₄Fe₁₃) could separate into two disconnected fields under shock pressure above 20 GPa, leading to the co-existence of Fe-rich and Fe-poor i-phases like the case in Khatyrka. In light of this, shock-recovery experiments do indeed offer an efficient method of constraining the impact conditions recorded by quasicrystal-bearing meteorite, and exploring formation conditions and mechanisms leading to quasicrystals.

Item Type:Article
Related URLs:
URLURL TypeDescription Information CentralArticle
Asimow, Paul D.0000-0001-6025-8925
Ma, Chi0000-0002-1828-7033
Bindi, Luca0000-0003-1168-7306
Additional Information:© 2020 International Union of Crystallography. This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited. Received 19 December 2019; Accepted 26 February 2020. We are grateful to Jeffrey Nguyen from Lawrence Livermore National Lab for providing the GDI. We thank Matthias Ebert and two anonymous reviewers for their constructive comments. We thank NASA Solar System Workings grant 80NSSC18K0532 for supporting JH and this research. The Lindhurst Laboratory for Experimental Geophysics at Caltech is also supported by NSF awards EAR-1725349 and 1829277. LB is funded by MIUR-PRIN2017, project 'TEOREM - deciphering geological processes using terrestrial and extraterrestrial ORE minerals', prot. 2017AK8C32 (PI: Luca Bindi). Analyses were carried out at the Caltech GPS Division Analytical Facility, which is supported, in part, by NSF Grants EAR-0318518 and DMR-0080065.
Funding AgencyGrant Number
Ministero dell’Istruzione, dell’Università e della Ricerca (MIUR)2017AK8C32
Subject Keywords:shock-wave experiments; graded density impactors; icosahedral quasicrystals; Khatyrka meteorite; phase transitions; planetary impacts; nanostructures
Issue or Number:3
PubMed Central ID:PMC7201281
Record Number:CaltechAUTHORS:20200511-101653760
Persistent URL:
Official Citation:First synthesis of a unique icosahedral phase from the Khatyrka meteorite by shock-recovery experiment. Hu, J., Asimow, P. D., Ma, C. & Bindi, L. (2020). IUCrJ 7, 434-444; doi: 10.1107/s2052252520002729
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:103098
Deposited By: Tony Diaz
Deposited On:11 May 2020 17:27
Last Modified:15 Feb 2022 22:20

Repository Staff Only: item control page