The dawn of 16 July 1945, when the United States began the Trinity test, the first atomic experiment conducted in the New Mexico Desert, was not just the beginning of a new era. The first atomic blast in fact also caused the totally accidental creation of the first quasicrystal. The extraordinary material was identified in the debris deposited that day more than eighty years ago in the large crater created by the bomb.
The authors of the discovery are the researchers of the international team led by Luca Bindi, professor at the Department of Earth Sciences. The study, published on PNAS, may also have implications for the strategy of nuclear deterrence. (Watch the video about Quasicrystals in the first nuclear explosion)
“The new material was accidentally formed during the first atomic test as the epilogue of the Manhattan project”, says Bindi, professor of Mineralogy of the University of Florence.“Detonation caused the melting of the surrounding sand, the test tower and the copper transmission lines that formed a glassy material known as trinitite”.
By studying the fragments of trinitite in the laboratories of the University of Florence it was discovered the oldest quasicrystal created by humans, which has a chemical composition so far unknown, Si61Cu30Ca7Fe2, linked to the conditions in which it was formed, and with a very peculiar characteristic: its date of creation is indelibly etched in history,” continues the scientist.
Quasicrystals are unique materials whose atoms are arranged as in a mosaic, in regular patterns but never repeating in the same way, as in ordinary crystals.
The first was created in the laboratory by Dan Shechtman in 1982 (work that earned him the Nobel Prize for Chemistry in 2011) and since then, because of their exceptional structure, these materials have been used in a variety of technological applications.
“Until today we knew that natural quasicrystals formed under extreme conditions of temperature and pressure: the only two that have been documented, icosahedrite and decagonite, had been found, thanks to my previous research, in fragments of a meteorite that fell into the Koryak mountains, far east of Russia, about 15,000 years ago,” explains Bindi. “The conditions under which the two quasicrystals had formed, probably in collisions between asteroids in space at the beginning of the solar system, are comparable to those produced in atomic explosions. This is why I decided to study the material formed in the Trinity test.”
One of the aspects of the discovery, which also involves fellows from the Universities of Princeton, Massachusetts, the California Institute of Technology, and the Los Alamos National Laboratory, has to do with actions to counter nuclear proliferation. This is because, unlike other debris formed as a result of nuclear explosions, the quasicrystals remain stable over time and could therefore testify the development of the explosions themselves.
“In addition to providing information on the consequences of an atomic explosion, our discovery opens up new horizons of research linked to the extraordinary conditions in which quasicrystals can be created,” concludes the Florentine researcher.