A team of researchers claims to have created the first materials that conduct electricity perfectly at room temperature and ambient pressure, but many physicists are highly sceptical. Speaking to New Scientist, Hyun-Tak Kim at the College of William & Mary in Virginia says he will support anyone trying to replicate his team’s work.

Superconductors are materials through which electricity can move without encountering any resistance, and so would significantly cut down the energy costs of electronics. But for over a century, researchers have been unable to make them work except under extreme conditions like very low temperatures and remarkably high pressures.

Now, Kim and his colleagues claim to have made a material that is superconductive at room temperature and pressure.

If their claims hold up to scientific scrutiny, this new work would be truly extraordinary, so the burden of proof for the research team is equally exceptional. The fact that some previous reports of breakthroughs in superconductivity were later retracted and that other teams failed to replicate the results also raises the stakes.

To make the new material, called LK-99, Kim and his colleagues mixed several powdered compounds containing lead, oxygen, sulphur and phosphorus, then heated them at a high temperature for several hours. This made the powders chemically react and transform into a dark grey solid.

The researchers then measured how much a millimetre-sized sample of LK-99 resisted electricity passing through it at different temperatures an