Nanodiamonds, perhaps an astrophysicists best friend

17 February 2012

Professor David McKenzie from the University of Sydney School of Physics has led a team that may give new understanding of why diamond is so common in space. Using computer simulations Professor McKenzie and his colleagues Nigel Marks and Martina Lattemann at Curtin University have shown how collisions in space between carbon dust particles can produce the tiny angular shaped crystals known as nanodiamonds.

Nanometer-sized diamond grains are commonly found in very old meteorites, but their origin is puzzling. "Originally our research was not linked with Astrophysics, but since our findings we have international interest from Astrophysicists in order to explain the presence of nanodiamonds in space and how they are formed," said Professor McKenzie.

New opportunities arise for their exploitation of nanodiamonds as a powerful astrophysical observational tool due to the fact that some nanodiamonds formed before our sun. These structures have the potential to tell us the environment in our region of the galaxy in those presolar times. "Nanodiamonds have the noble gas xenon inside them, but it isn't xenon from the sun, it is from other parts of the universe, possibly before the sun existed," said Professor McKenzie.

"The simulation of this process was suggested by experimentation that had surprising results. Once we conducted the simulation, we not only had confirmation of our experiment, but we had identified the mechanics of the process, it was our lightbulb moment" explained Professor McKenzie.

A computer simulation of nanodiamond formation from carbon onions. Image Credit: Professor David Mckenzie.
A computer simulation of nanodiamond formation from carbon onions. Image Credit: Professor David Mckenzie.

Nanodiamonds are formed in space in a two step process. The first step is the condensation of carbon vapor to form carbon onions which consist of multi-layered carbon structures called fullerenes. The second step is an energetic impact of these onions. "Carbon onions are common in space, and when they collide, they create nanodiamonds," said Professor McKenzie

"This process is consistent with common environments in space and invokes the fewest assumptions of any proposed model," continued Professor McKenzie.

"A major strength of our model for nanodiamond formation is its correspondence with realistic conditions known from materials science and astrophysics." Further, said Professor McKenzie "This process was not previously considered and through our research we have reached an interdisciplinary audience."

"This research leads us to a technology for recreating the nanodiamond from meteors in the laboratory." Said Professor McKenzie about future direction for the team.

Contact: Katynna Gill

Phone: 02 9351 6997

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