Valery Levitas, Anson Marston Distinguished Professor in Engineering/Vance Coffman Faculty Chair Professor in Aerospace Engineering, and former Levitas student and post-doctoral researcher Biao Feng are part of a team of scientists from Iowa State University, Texas Tech and Cal Tech that have published a research paper in Carbon, a highly ranked material journal. Feng currently works at the Los Alamos National Laboratory.
In the paper, “Shear driven formation of nano-diamonds at sub-gigapascals and 300 K”, Carbon, 2019, Vol. 146, 364-368, the team reports multiscale theoretical predictions and experimental confirmations of the possibility of obtaining different types of diamond from graphite at room temperature under plastic shear and record low pressure. Diamond was obtained at just 0.7 GPa, 100 times lower than under hydrostatic pressure! In addition, new orthorhombic diamond phase was revealed.
This discovery represents the culmination of a two-decade effort of the Levitas team and has several important consequences, including: proving that plastic shear is an extremely important tool for searching for new and known high-pressure phases at economically favorable conditions; possible new industrial diamond synthesis technology if the process is scaled up; and significant implications for revealing the Earth’s geological history and the graphite-to-diamond transformation in continental crust without necessity of its subduction by 100 km to high temperature and pressure region followed by uplifting.
Levitas also holds an appointment in Iowa State’s Department of Mechanical Engineering and is a faculty scientist at Ames Laboratory.
The full research abstract can be found here.