- Award ID(s):
- 2049620
- Publication Date:
- NSF-PAR ID:
- 10301032
- Journal Name:
- Minerals
- Volume:
- 11
- Issue:
- 6
- Page Range or eLocation-ID:
- 567
- ISSN:
- 2075-163X
- Sponsoring Org:
- National Science Foundation
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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-phasemore »
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