Scientists use computation to design a super-light crystalline aluminium

1 min read

Aluminium is already highly prized for its conductivity, low melting point, strength when alloyed, imperviousness to rust and, above all, it’s extremely light weight. Now, researchers from Utah State University and Southern Federal University in Rostov-on Don, Russia have used computational design to conceive a form of crystalline aluminium with an even lower density than standard aluminium.

USU chemist and researcher, Alexander Boldyrev, said: “They started with a known crystal lattice, in this case, a diamond, and substituted every carbon atom with an aluminium tetrahedron.”

The resulting crystalline aluminium, called supertetrahedral aluminium, has a density of just 0.61 grams per cubic centimetre, compared to the density of normal aluminium, which is 2.7g/cm3. Steel, by comparison, has a density of 7.75g/cm3.

This means that a lump of the crystalline aluminium would float on water, which has a density of 1g/cm3, where a lump of ordinary aluminium would sink to the bottom. According to the researchers, these properties would make it useful for applications in spaceflight, medicine, wiring and more lightweight, more fuel-efficient automotive parts. Spaceflight would be important because every kilogram added to a rocket's payload increases the cost and difficulty of launching.

But Boldyrev added that, while it would be inexpensive to produce and the computation indicates high plasticity, the team hasn’t manufactured it yet. But, there's still a lot to learn about it. For example, how strong it is.

The next step for the researchers is to try to produce supertetrahedral aluminium so it can be examined more closely.