In their research, a team of physicists from UNLV’s Nevada Extreme Conditions Laboratory (NEXCL) used a research instrument like the one pictured, a diamond anvil cell, to lower the pressure needed to observe a material capable of superconductivity at room temperature. Credit: Image courtesy of NEXCL
Less than two years ago, the scientific world was shocked by the discovery of a material capable of superconducting at room temperature. Now, a team of University of Nevada Las Vegas (UNLV) physicists has once again raised the bar by reproducing the feat at the lowest pressure ever recorded.
To be clear, this means science is closer than ever to a usable, repeatable material that could one day revolutionize the transport of energy.
It made international headlines with the discovery of 2020. superconductivity at room temperature for the first time By UNLV physicist Ashkan Salamat and University of Rochester physicist colleague Ranga Dias. To achieve this feat, the scientists chemically synthesized a mixture of carbon, sulfur, and hydrogen first into a metallic state and then into a superconducting state at room temperature using conditions of extremely high pressure – 267 gigapascals – that you will only find. Nature near the center of the earth.
Fast forward to less than two years, and researchers are now able to complete this feat at just 91 GPa – roughly a third of the originally reported pressure. The new findings are published as a preliminary article in the journal. Chemical Communications this month.
And Super Discovery
By fine-tuning the composition of carbon, sulfur, and hydrogen used in the original invention, the researchers are now able to produce a material at lower pressure that retains its superconducting state.
“These are pressures at a level that is difficult to understand and assess outside of the lab, but our current trajectory shows that it is possible to reach relatively high superconducting temperatures at consistently lower pressures – that’s our ultimate goal,” said Gregory Alexander Smith, lead author of the study. and graduate student researcher with UNLVs Nevada Extreme Conditions Lab (NEXCL). “At the end of the day, if we want to make devices that are useful to societal needs, we have to reduce the pressure needed to create them.”
Although the pressures are still very high – nearly a thousand times higher than what you would experience at the bottom of the Mariana Trench in the Pacific Ocean – they continue to race towards a near-zero target. It’s an exponential race at UNLV as researchers better understand the chemical relationship between the carbon, sulfur, and hydrogen that make up the material.
“Our knowledge of the relationship between carbon and sulfur is advancing rapidly and we are finding rates that lead to quite different and more efficient responses than those initially observed,” said Salamat, who leads UNLV’s NEXCL and contributed to the latest research. study. “Observing such different phenomena in a similar system only shows the richness of Mother Nature. There is more to understand, and each new development brings us a little closer to the abyss of everyday superconducting devices.”
The Holy Grail of Energy Efficiency
Superconductivity is a remarkable phenomenon, first observed more than a century ago, but only at remarkably low temperatures that preclude any thought of practical application. Only in the 1960s did scientists theorize that this feat was possible at higher temperatures. Salamat and his colleagues’ discovery of a room-temperature superconductor in 2020 excited the scientific world as the technology supports the flow of electricity with zero resistance, meaning that energy passing through a circuit can be transmitted infinitely and without loss of power. This could have significant implications for energy storage and transmission, supporting everything from better cell phone batteries to a more efficient energy grid.
“The global energy crisis shows no signs of slowing down, and costs are rising in part due to the US power grid losing about $30 billion a year due to the inefficiency of current technology,” said Salamat. “We need to lead technology for social change, and I believe the work done today is at the forefront of tomorrow’s solutions.”
According to Salamat, the properties of superconductors could support the next generation of materials that could fundamentally change the energy infrastructure in the US and beyond.
“Imagine harnessing energy in Nevada and sending it across the country with no energy loss,” he said. “This technology could one day make that possible.”
Reference: G. Alexander Smith, Ines E. Collings, Elliot Snider, Dean Smith, Sylvain Petitgirard, Jesse S. Smith, Melanie White, Elyse Jones, Paul “Carbon content, high temperature superconductivity below 100 GPa in carbonaceous sulfur hydride directs” Ellison, Keith V. Lawler, Ranga P. Dias and Ashkan Salamat, July 7, 2022, Chemical Communications.
DOI: 10.1039/D2CC03170A
Smith, the lead author, is a former UNLV undergraduate researcher in Salamat’s lab and a current doctoral student in chemistry and research with NEXCL. Other study authors include UNLV with Salamat, Dean Smith, Paul Ellison, Melanie White, and Keith Lawler; Ranga Dias, Elliot Snider and Elyse Jones of the University of Rochester; Ines E. Collings with Swiss Federal Laboratories for Materials Science and Technology, Sylvain Petitgirard with ETH Zurich; and Jesse S. Smith of Argonne National Laboratory.
