Boffins coax non-superconductive stuff into dropping the 'non'

The ultimate goal: A room temperature superconductor

Physicists claim to have developed a method that forces a non-superconducting material into a superconductive state, according to research published today.

Superconductivity is a phenomenon where a material has zero resistance and perfect conductivity. It would be incredibly useful, if superconductivity wasn’t so hard to achieve. It takes a lot of effort to chill a material below the critical temperature where superconductivity magically kicks in.

The paper, published in the Proceedings of the National Academy of Sciences of the United States of America, shows that a technique that makes non-superconducting materials superconductive could also raise the critical temperature of future superconductors.

The team put two layers of calcium iron arsenide (CaFe2As2) crystals into a vacuum and heated the material to 850°C (1,562°F). It was annealed over 24 hours before being dumped in an ice bath.

At 350°C (662°F), it went through a second round of annealing, where researchers discovered a narrow time window at which superconductivity emerged.

Dr Chu, coauthor of the paper, told The Register the idea that superconductivity could be induced at the interface between two non-superconductive materials was first proposed in the 1970s, but hasn’t been proved until now.

The team used x-ray diffraction to observe the material during its superconductive period. “During that time, the two phases of the material intertwine and stabilize,” Chu explained.

The critical temperature for calcium iron arsenide is 25K (-415°F) – much lower than the current highest critical temperature at 134K (-218°F).

Although the critical temperature is low, the technique of annealing and quenching material at its interface could enhance superconductors in the future.

Dr Paul Chu said that the ultimate goal is to eventually create a room temperature superconductor.

The applications for room temperature superconductors are far reaching. It could affect everything from “energy storage to levitating magnetic trains,” Chu told The Register. ®