Boron: Physics’ latest superconductive material

31 Mar 2016

There’s a decent chance that boron is the only natural two-dimensional superconductive element on Earth, following the discovery of its unique low-temperature properties.

Researchers at Rice University in Texas have established that boron is a resistance-free superconductor in the right environment, moving one major step beyond the fact that was previously accepted in theory.

The problem – there’s always one – is its superconductivity only becomes apparent in extremely low temperatures: -256oC, however, it’s probably the only 2D superconductor around, so very small circuits are primed for a boron fix.

Everybody is at it

Evgeni Penev, Alex Kutana and Boris Yakobson published their paper on the discovery at the same time that samples of the materials began being made in labs in the US and China. This was an inevitable development after an earlier paper from Yakobson and his colleagues predicted how it could be made.

In the 100 years since superconductivity was established, never before had it been tested on boron, according to Penev, who noted the lightness of its atomic mass was always appealing.

“If it’s metallic too, these are two major prerequisites for superconductivity. That means at low temperatures, electrons can pair up in a kind of dance in the crystal,” he said.

“Lower dimensionality is also helpful,” Yakobson said. “It may be the only, or one of very few, two-dimensional metals. So there are three factors that gave the initial motivation for us to pursue the research. Then we just got more and more excited as we got into it.”

Versatility abounds

Penev said that boron works as, given its opposite momenta and spins, it creates what are called Cooper pairs. This means they attract each other at low temperatures with the help of lattice vibrations, giving it superconductive properties.

“We’ve been working to characterise boron for years, from cage clusters to nanotubes to planer sheets, but the fact that these papers appeared so close together means these labs can now test our theories,” Yakobson said.

Boron is quite a versatile material, recently used in a project to successfully drag water-splitting solar energy production one step closer to reality.

A boron-doped photovoltaic project between the Tyndall National Institute in Cork, Queen’s University in Belfast and Stanford University in California recently broke the record for generating a voltage from a solar cell submerged in water.

Main boron image via Shutterstock

Gordon Hunt was a journalist with Silicon Republic