To reach their conclusions, the scientists used the latest detailed crystallographic and spectroscopic examination of the mineral lonsdaleite from the iron meteorite Canyon Diablo, which was first discovered in the Arizona desert in 1891.
Named after the pioneering British crystallologist Dame Kathleen Lonsdale, it was previously thought to be composed of pure hexagonal diamonds, which distinguishes them from classic cubic diamonds. However, the team found that it actually consists of nanostructured diamond and graphene-like interlayers – where two minerals grow together into crystals – called diaphytes. The team also identified stacking errors, or “errors,” in the repeating sequence of the atomic layer pattern.
“By studying the different types of growth between graphene and the structure of diamond, we can get closer to understanding the pressure and temperature conditions that occurred during an asteroid impact,” study lead author Peter Nemeth said in an informative statement.
Nemeth and his colleagues also found that the spacing between graphene layers is unusual due to the unique environment of carbon atoms that occur at the interface between diamond and graphene. They also demonstrated that the structure of the diaphragm was responsible for previously unexplored spectroscopic benefits.
“This is very exciting because we can now reveal the diaphragm structure in diamond using simple spectroscopic techniques without the need for an expensive and laborious electron microscope,” said study co-author Chris Howard.
Depending on the group, the structural units and complexities reported in lonsdaleite samples may result from shock and static stress or precipitation from the vapor phase in a wide variety of other carbonaceous materials.
Thus, they believe that through controlled evolution of the layer structure, it should be possible to design materials that are extremely strong and flexible, as well as electronic properties that can be modified from conductor to insulator.
