Researchers create first self-assembled superconductor

It is the first time a superconductor, in this case niobium nitride, has self-assembled into a porous, 3-D gyroidal structure

Researchers at Cornell University have blazed a new trail by creating a self-assembled, three-dimensional superconductor.

It is the first time a superconductor, in this case niobium nitride (NbN), has self-assembled into a porous, 3-D gyroidal structure, said lead researcher Ulrich Wiesner, a material science and engineering professor.

The gyroid is a complex cubic structure based on a surface that divides space into two separate volumes that are inter-penetrating and contain various spirals.

"We are saying to the superconducting community, 'Hey, look guys, these organic block copolymer materials can help you generate completely new superconducting structures and composite materials, which may have novel properties and transition temperatures. This is worth looking into,'" Wiesner said.

The findings appeared in the journal Science Advances.

Currently, superconductivity for practical uses such as in magnetic resonance imaging (MRI) scanners and fusion reactors is only possible at about near -273 degrees Celsius, although recent experimentation has yielded superconducting at a comparatively balmy -70 degrees Celsius.

"There is this effort in research to get superconducting at higher temperatures, so that you do not have to cool anymore," Wiesner said.

"That would revolutionise everything. There is a huge impetus to get that," Wiesner explained.

In the first attempt to achieve superconductivity, the niobium oxide was heated to a temperature of 700 degrees Celsius.

After cooling the material to room temperature, it was determined that superconductivity had not been achieved. The same material was then heated to 850 degrees, cooled and tested, and superconductivity had been achieved.

"We tried going directly to 850, and that did not work," Wiesner said.

"So we had to heat it to 700, cool it and then heat it to 850 and it worked," Wiesner noted.