This illustration shows the diamond-like structure of the new, metastable, ultra-light crystalline form of aluminum. Image: Iliya Getmanskii, Southern Federal University, Russia.If you drop an aluminum spoon in a sink full of water, the spoon will sink to the bottom. That's because aluminum, in its conventional form, is denser than water, explains chemist Alexander Boldyrev from Utah State University. But if you restructure the common household metal at the molecular level, as Boldyrev and colleagues did using computational modeling, you could produce an ultra-light crystalline form of aluminum that's lighter than water.
Boldyrev, together with scientists Iliya Getmanskii, Vitaliy Koval, Rusian Minyaev and Vladimir Minkin from Southern Federal University in Rostov-on Don, Russia, report their findings in a paper in The Journal of Physical Chemistry C. The team's research is supported by the US National Science Foundation and the Russian Ministry of Science and Education.
"My colleagues' approach to this challenge was very innovative," says Boldyrev, professor in USU's Department of Chemistry and Biochemistry. "They started with a known crystal lattice, in this case, a diamond, and substituted every carbon atom with an aluminum tetrahedron."
The team's calculations confirmed that this would produce a new, metastable, lightweight form of crystal aluminum. To their amazement, this crystal aluminum has a density of only 0.61 gram per cubic centimeter, in contrast to convention aluminum's density of 2.7 grams per cubic centimeter.
"That means the new crystallized form will float on water, which has a density of one gram per cubic centimeter," Boldyrev says. The low density of this crystallized form opens up a whole new realm of possible applications for the non-magnetic, corrosive-resistant, abundant, relatively inexpensive and easy-to-produce metal.
"Spaceflight, medicine, wiring and more lightweight, more fuel-efficient automotive parts are some applications that come to mind," Boldyrev says. "Of course, it's very early to speculate about how this material could be used. There are many unknowns. For one thing, we don't know anything about its strength."
Still, he says, the breakthrough discovery marks a novel way of approaching material design. "An amazing aspect of this research is the approach: using a known structure to design a new material," Boldyrev says. "This approach paves the way for future discoveries."
This story is adapted from material from Utah State University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.