Scientists as the Department of Energy’s SLAC National Accelerator Laboratory and Stanford University have created what they say is the first nickel oxide material that shows clear signs of superconductivity. The material can transmit electrical current with no loss.
The material, known as nickelate, is the first in a potential new family of unconventional superconductors that’s very similar to the copper oxides, or cuprates, discovered in 1986. The material brings the possibility that superconductors might someday operate at close to room temperature. A room-temperature superconductor could revolutionize electronics.
There are some significant mysteries about the new nickelate superconductor. One big one is that the material may not have the magnetism that all superconducting cuprates have. That could change leading theories on how unconventional superconductors work.
The scientists on the team say that making nickelate with an atomic structure that supports superconductivity is “unexpectedly hard.” The team says that the nickelate they were trying to make was not stable at the very high temperatures of about 600 degrees Celsius where the materials are normally grown.
The team started with perovskite, a material that has a double-pyramid atomic structure containing neodymium, nickel, and oxygen. The material was doped with strontium, a common process that adds a chemical that makes electrons in the material flow more freely. That process removed nickel atoms leaving holes as you would see when playing the game Jenga when the blocks are removed.
When that material was loosely wrapped in aluminum foil and sealed in a test tube with a chemical that took away a layer of oxygen atoms the film flipped into a new atomic structure known as a strontium-doped nickelate. More testing showed that the new material was superconducting in a temperature range of 9-15 kelvins with potentially higher temperatures possible. The team says the work is in a “very, very early stage “with much work ahead.