May 22 2015
A team of researchers, headed by Academy Research Fellow Pekka Koskinen of the Nanoscience Center at the University of Jyväskylä, has successfully performed computer simulations forecasting a liquid phase in atomically thin golden islands that form patches on small graphene pores.
This innovative prediction paves the way for probable phases of materials further than before. Up until graphene’s discovery a decade ago, it was believed that 2D materials did not exist. Nevertheless, these materials have been observed, but exclusively in the solid as the thermal atomic motion needed for molten materials can easily break the thin and delicate membrane. Thus, it was concluded that atomically thin flat liquid was not impossible.
Based on the simulations, the researchers noticed how gold atoms flow and modify places in the plane, and how the graphene template surrounding it maintains the liquid membrane’s planarity.
"Here the role of graphene is similar to circular rings through which children blow soap bubbles. The liquid state is possible when the edge of graphene pore stretches the metallic membrane and keeps it steady," Koskinen says.
Computer simulations, with the aid of quantum-mechanical models and nanostructures with numerous gold atoms, enabled prediction of the liquid phase. The prediction has been published in the esteemed journal Nanoscale. As of now, the liquid phase is present only in the computer simulations obtained and awaits experimental confirmation.
"Unfortunately, simulations suggest that the flat liquid is volatile. In experiments the liquid membrane might burst too early, like a soap bubble that bursts before one gets a proper look at it. But again, even graphene was previously considered too unstable to exist," Koskinen says.
Source: http://www.aka.fi/