Putting the Squeeze on Hydrogen and Sodium for Superconductivity

Superconductivity is a hot phenomenon that occurs only at very cold temperatures. Finding ways to change that and make superconductivity practical at higher temperatures is a major goal for physicists and engineers. One possibility involves the metallic phase of hydrogen, theorized to be superconducting at ambient temperatures but yet to be achieved in practice. By synthesizing a compound of hydrogen with sodium using the U.S. Department of Energy’s Advanced Photon Source (APS), an Office of Science user facility, experimenters have achieved a new class of sodium polyhydrides, taking a highly promising first step toward achieving practical high-temperature, ambient pressure superconductivity. The unusual linear electronic structure of these polyhydrides lends itself to the creation of new metallic materials with superconducting properties at higher temperatures than previously possible. They may also be useful for hydrogen storage applications in fuel cells.