A small team of researchers from the U.S. and Italy has found evidence of a naturally formed quasicrystal in a sample obtained from the Khatyrka meteorite. In their paper published in the journal Scientific Reports, the team describes how they found the quasicrystal and offer some possible explanations on how it was formed.
Prior to the 1980's, scientists believed there were just two types of solids; crystals and amorphous solids. Crystals are materials made of atoms that are joined in a repeating lattice. Amorphous solids are rather the opposite, having no real order. But then researchers discovered that another type of structure could exist, at least theoretically—quasicrystals. They are made of latticed atoms, like crystals, but do not repeat. After establishing their existence, researchers began making them in labs—over 100 have been created thus far. At the time, it was not clear if quasicrystals could exist naturally, though some suggested there was no reason for them not to come about under conditions similar to those used in labs—thus began a search for an example.
That search came to fruition in 2009, as a team studying samples from the Khatyrka meteorite in northeastern Russia found two examples of quasicrystals that were of the same type that had been made in the lab. In this new effort, the researchers report that they have found a third quasicrystal from the same meteorite sample, but this one has never been made artificially before—it is also very similar to one of the other two quasicrystals found in the meteorite. All three have metallic aluminum, which, the team notes, bonds well with oxygen. The newest one also has iron and copper.
Though they have no way to prove it, the researchers suggest it is possible the quasicrystals came about due to a collision between asteroids—such a violent impact would provide both the heat and energy needed to cause the unique formations. They suggest that further study of the specimens could lead to a better understanding of the early solar system. The discovery also offers fresh hope that naturally occurring quasicrystals could be found that originated on Earth.
This article has been republished from materials provided by Scientific Reports. Note: material may have been edited for length and content. (Original written by Bob Yirka.) For further information, please contact the cited source.
L. Bindi,et al. Collisions in outer space produced an icosahedral phase in the Khatyrka meteorite never observed previously in the laboratory, Scientific Reports, 2016; DOI: 10.1038/srep38117