Scientists invent superconductive material that works at practical temperatures

The University of Rochester researchers have created a superconducting material that functions at both a temperature and pressure low enough for practical applications.

“With this material, the dawn of ambient superconductivity and applied technologies has arrived,” said the press release, which was published today by a team led by Ranga Dias, an assistant professor of mechanical engineering and physics. 

The new material is a nitrogen-doped lutetium hydride (NDLH) that exhibits superconductivity at 69 degrees Fahrenheit and 10 kilobars (145,000 pounds per square inch, or psi) of pressure.

Hydrides created by combining rare earth metals with hydrogen, then adding nitrogen or carbon, have provided researchers with an inspiring “working recipe” for creating superconducting materials in recent years. 

However, the resulting compounds become superconductive at temperatures or pressures that are still not practical for applications.

A good candidate

To overcome this issue, Dias looked elsewhere along the periodic table. He considered lutetium as “a good candidate to try.” The material has highly localized fully-filled 14 electrons in its f orbital configuration that suppress the phonon softening and provide enhancement to the electron-phonon coupling needed for superconductivity to take place at ambient temperatures. 

“The key question was, how are we going to stabilize this to lower the required pressure? And that’s where nitrogen came into the picture,” said Dias.

Nitrogen has a rigid atomic structure that can be used to create a cage-like lattice within a material providing the stability for superconductivity to occur at lower pressure.

Dias and his team engineered a gas mixture of 99 percent hydrogen and one percent nitrogen, placed it in a reaction chamber with a pure sample of lutetium, and let the components react for two to three days at 392 degrees Fahrenheit.

A significant bright red color

The resulting mixture went through several states and colors before reaching a bright red non-superconducting metallic state.

“It was a very bright red,” Dias said. “I was shocked to see colors of this intensity.” The end result however could not be denied. The new material was superconductive at both a temperature and pressure low enough for practical applications.

“A pathway to superconducting consumer electronics, energy transfer lines, transportation, and significant improvements of magnetic confinement for fusion are now a reality,” Dias concluded. “We believe we are now at the modern superconducting era,” Dias added.

The study was published in Nature.