While researching at the ELKH Astronomy and Earth Sciences Research Center (CSFK) and the ELKH Energy Science Research Center (EK), a lonsdaleite mineral found in the Arizona desert was studied in 1891, from the Canyon Diablo iron meteorite. The research was conducted by an international research group using the latest techniques of electron microscopy, crystallography and spectroscopy.
During the investigation it was:
The shock waves from asteroids colliding with Earth create special diamond-like materials, with controlled production from which the very tough and plastic materials can be engineered.
During the collision of an asteroid, a shock wave of high energy and speed is generated, which can generate high temperatures and extreme pressure for a short period of time. A special geological process favors the development of non-equilibrium conditions and the formation of materials with exceptional properties.
Peter Nemeth, Senior Scientific Assistant at CSFK’s Institute of Geology and Geochemistry, and Zolt Fogarassi, Ellis Levente and Bella Beach, researchers at the European Commission’s Institute of Technical Physics and Materials Science, participated in the research with their foreign colleagues. Based on the investigation, it was revealed that the lonsdaleite mineral with unique properties, which was created during an asteroid impact about fifty thousand years ago, is actually a so-called diaphyte consisting of various variations of diamond-graphite nanostructures, which is in fact the common structure. of the two substances in a single crystal lattice. In the metal, many layer faults that occur in the repetitive patterns of the atomic layers can also be observed.
Identification of the different types of intercalation between graphene and diamond structures may contribute to a better understanding of the pressure and temperature conditions that occur during an asteroid impact. Due to the unique environment of carbon atoms at the interface between diamond and graphene, the distance between graphene layers is significantly different from normal. Based on the research, the structure of the diaphragm is responsible for the emergence of the hitherto unexplained spectral Raman band. Thanks to this identification, sheet structures in diamond can now be identified with a simple spectroscopic technique.
Complex structures in the sample may occur in other carbon materials. Not only the dynamic shock wave generated during the asteroid impact, but also the static pressure at high pressure and temperature, as well as the chemical vapor phase separation can create like structures. Through the controlled growth of granular layers, it is possible to design highly rigid and flexible materials with tunable electronic properties from conductor to insulator.
This discovery paves the way for the design of new types of diamond-like materials with mechanical and electronic properties,
Thus, new applications can be created in many industrial fields, from abrasives to electronics and nanomedicine to laser technology.
The researchers pay tribute to the late co-author Professor Paul Macmillan, who played an important role in the group’s success in diamond exploration. The project was implemented with the support of the NKFI Fund and the János Bolyai Research Grant of the Hungarian Academy of Sciences, among others.
The results have been published in the international journal Proceedings of the National Academy of Sciences study also appeared.
Opening photo: MTI/EPA/Pedro Puente Hoyos
