Communications of the ACM
Supercomputers Reveal Strange, Stress-Induced Transformations in World's Thinnest Materials
Researchers from Columbia University used supercomputers at Brookhaven National Laboratory to map and compare the transformations and breaking points of promising monolayers.
Credit: Brookhaven National Laboratory
Columbia University researchers used Brookhaven National Laboratory supercomputers to map and compare the transformations and breaking points of graphene and other promising monolayers.
The researchers identified the breaking mechanism of several monolayer materials hundreds of times stronger than steel with exotic properties. They found straining the materials induced a novel phase transition, and the phenomenon persisted across several different materials with disparate electronic properties, suggesting monolayers may have intrinsic instabilities to be either surmounted or exploited.
"To see the beautiful patterns exhibited by these materials at their breaking points for the first time was enormously exciting--and important for future applications," says Columbia researcher Eric Isaacs.
The researchers used a mathematical framework called density functional theory (DFT) to describe the quantum mechanical processes unfolding in the materials. "DFT lets us study materials directly from fundamental laws of physics, the results of which can be directly compared to experimental data," says Columbia professor Chris Marianetti.
As the monolayers were strained, the energy expenditure of changing the bond lengths became significantly weaker, meaning under sufficient stress, the emergent soft mode encourages the atoms to reconfigure themselves into unstable arrangements, which dictates how one might control that strain and tune monolayer performance.
From Brookhaven National Laboratory
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Abstracts Copyright © 2014 Information Inc., Bethesda, Maryland, USA
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