Impact-induced shock and the formation of natural quasicrystals in the early solar system
Impact-induced shock and the formation of natural quasicrystals in the early solar system
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DOI：
10.1038/ncomms5040
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发表时间：
2014-06-01
影响因子：
16.6
通讯作者：
Steinhardt, Paul J.
中科院分区：
文献类型：
--
作者：
Hollister, Lincoln S.;Bindi, Luca;Steinhardt, Paul J.
在CV 3碳质球粒陨石Khatyrka中发现了一种天然准晶，二十面陨铁（Al 63 Cu 24 Fe 13），伴随着Khatyrkite（CuAl 2）和Cupalite（CuAl），这对这些金属合金的形成和保存提出了一个谜。在这里，我们提出了一系列证据，包括在CV 3球粒陨石中发现了以前从未观察到的高压相，表明冲击波产生了压力和温度的不均匀分布，其中某些部分至少达到5GPa和1，200摄氏度。这些条件足以使含铝铜矿物熔化，然后快速凝固成二十碳六角闪石和其他铝铜金属相。陨石还含有迄今未观察到的铁镍和硫化铁相，以及大量的Al和Cu。这些相在Khatyrka中的存在进一步证明了Al-Cu合金是早期太阳系中发生的不寻常过程的自然产物。
The discovery of a natural quasicrystal, icosahedrite (Al63Cu24Fe13), accompanied by khatyrkite (CuAl2) and cupalite (CuAl) in the CV3 carbonaceous chondrite Khatyrka has posed a mystery as to what extraterrestrial processes led to the formation and preservation of these metal alloys. Here we present a range of evidence, including the discovery of high-pressure phases never observed before in a CV3 chondrite, indicating that an impact shock generated a heterogeneous distribution of pressures and temperatures in which some portions reached at least 5GPa and 1,200 degrees C. The conditions were sufficient to melt Al-Cu-bearing minerals, which then rapidly solidified into icosahedrite and other Al-Cu metal phases. The meteorite also contains heretofore unobserved phases of iron-nickel and iron sulphide with substantial amounts of Al and Cu. The presence of these phases in Khatyrka provides further proof that the Al-Cu alloys are natural products of unusual processes that occurred in the early solar system.