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First synthesis of a unique icosahedral phase from the Khatyrka meteorite by shock-recovery experiment
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 Al(62)Cu(31)Fe(7), referred to as i-phase II, is unique because it deviates...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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International Union of Crystallography
2020
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7201281/ https://www.ncbi.nlm.nih.gov/pubmed/32431827 http://dx.doi.org/10.1107/S2052252520002729 |
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author | Hu, Jinping Asimow, Paul D. Ma, Chi Bindi, Luca |
author_facet | Hu, Jinping Asimow, Paul D. Ma, Chi Bindi, Luca |
author_sort | Hu, Jinping |
collection | PubMed |
description | 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 Al(62)Cu(31)Fe(7), 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, Al(2)Cu), 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)Cr(4)Ni(1.8)), together with stolperite and hollisterite (λ, Al(13)Fe(4)), 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 (Al(63)Cu(24)Fe(13)) 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. |
format | Online Article Text |
id | pubmed-7201281 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | International Union of Crystallography |
record_format | MEDLINE/PubMed |
spelling | pubmed-72012812020-05-19 First synthesis of a unique icosahedral phase from the Khatyrka meteorite by shock-recovery experiment Hu, Jinping Asimow, Paul D. Ma, Chi Bindi, Luca IUCrJ Research Papers 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 Al(62)Cu(31)Fe(7), 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, Al(2)Cu), 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)Cr(4)Ni(1.8)), together with stolperite and hollisterite (λ, Al(13)Fe(4)), 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 (Al(63)Cu(24)Fe(13)) 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. International Union of Crystallography 2020-03-26 /pmc/articles/PMC7201281/ /pubmed/32431827 http://dx.doi.org/10.1107/S2052252520002729 Text en © Hu et al. 2020 http://creativecommons.org/licenses/by/4.0/ 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.http://creativecommons.org/licenses/by/4.0/ |
spellingShingle | Research Papers Hu, Jinping Asimow, Paul D. Ma, Chi Bindi, Luca First synthesis of a unique icosahedral phase from the Khatyrka meteorite by shock-recovery experiment |
title | First synthesis of a unique icosahedral phase from the Khatyrka meteorite by shock-recovery experiment |
title_full | First synthesis of a unique icosahedral phase from the Khatyrka meteorite by shock-recovery experiment |
title_fullStr | First synthesis of a unique icosahedral phase from the Khatyrka meteorite by shock-recovery experiment |
title_full_unstemmed | First synthesis of a unique icosahedral phase from the Khatyrka meteorite by shock-recovery experiment |
title_short | First synthesis of a unique icosahedral phase from the Khatyrka meteorite by shock-recovery experiment |
title_sort | first synthesis of a unique icosahedral phase from the khatyrka meteorite by shock-recovery experiment |
topic | Research Papers |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7201281/ https://www.ncbi.nlm.nih.gov/pubmed/32431827 http://dx.doi.org/10.1107/S2052252520002729 |
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