The RMIT team’s images showed that the regular diamonds only form in the middle of these Lonsdaleite veins using this new method developed by the inter-institutional team. Credit: RMIT
An international team of scientists has defied nature to create diamonds in a laboratory at room temperature in minutes – a process that typically requires billions of years, enormous pressure and extremely hot temperatures.
The team, led by The Australian National University (ANU) and RMIT University made two types of diamonds: the one found on an engagement ring and another type of diamond called Lonsdaleite, which occurs naturally at the site of meteorite impacts such as Canyon Diablo in the United States.
One of the leading researchers, ANU professor Jodie Bradby, said their breakthrough shows that Superman may have had a similar trick up his sleeve when he crushed coal into diamond without using his heat ray.
“Natural diamonds are usually formed over billions of years, about 150 kilometers deep in the earth, where there are high pressures and temperatures above 1,000 degrees Celsius“Said Professor Bradby of the ANU Research School of Physics.
ANU Professor Jodie Bradby holds the diamond anvil that the team used to create the diamonds in the laboratory. Photo credit: Jamie Kidston, ANU
The team, which includes former ANU PhD student Tom Shiell, who is now working at the Carnegie Institution for Science, previously only made Lonsdaleite at high temperatures in the laboratory.
This new unexpected discovery shows that both lonsdaleite and normal diamond can form at normal room temperatures if only high pressure is applied – that’s the equivalent of 640 African elephants on the tip of a ballet shoe.
“The twist in history is how we apply the pressure. In addition to very high pressures, we also let the carbon experience something called “shear” – which is like a twisting or sliding force. We believe this will allow the carbon atoms to move in place and form lonsdaleite and regular diamonds, ”said Professor Bradby.
Co-lead researcher Professor Dougal McCulloch and his team at RMIT used advanced electron microscopic techniques to capture solid and intact sections from the experimental samples and to take snapshots of the formation of the two types of diamond.
“Our images showed that using this new method developed by our interinstitutional team, the regular diamonds only form in the middle of these Lonsdaleite veins,” said Professor McCulloch.
Doctoral student Brenton Cook (left) and Prof. Dougal McCulloch with one of the electron microscopes used in research. Credit: RMIT
“Seeing these little ‘rivers’ of Lonsdaleite and regular diamonds for the first time was just amazing and really helps us understand how they could form.”
Lonsdaleite, named after the crystallographer Dame Kathleen Lonsdale, the first woman to be elected as a Fellow to the Royal Society, has a different crystal structure than regular diamond. It is predicted to be 58 percent more difficult.
“Lonsdaleite has the potential to cut through ultra-strength materials on mining sites,” said Professor Bradby.
“Creating more of this rare but very useful diamond is the long-term goal of this work.”
Ms. Xingshuo Huang is an ANU PhD student who works in Professor Bradby’s laboratory.
“It was exciting to be able to make two types of diamonds at room temperature in our laboratory for the first time,” said Ms. Huang.
The team, which involved the University of Sydney and Oak Ridge National Laboratory in the United States, published the research results in the journal Small.
Reference: “Investigation of the room temperature formation of the ultra-hard nanocarbons diamond and Lonsdaleit” by Dougal G. McCulloch, Sherman Wong, Thomas B. Shiell, Bianca Haberl, Brenton A. Cook, Xingshuo Huang, Reinhard Boehler and David R. McKenzie and Jodie E. Bradby , November 4, 2020, Small.
DOI: 10.1002 / smll.202004695
