Superconductors at Room Temperature: Fact or Fiction?
09-03-2023 | By Robin Mitchell
Recently, researchers from the University of Rochester announced that they had created a room-temperature superconductor that operates with zero resistance under high pressures and temperatures using hydrogen-rich compounds, such as nitrogen-doped lutetium hydride. While many are excited with the announcement of this breakthrough, some remain sceptical given the scrutiny around previous cases of research malfeasance, such as the retracted paper on fabricated data about superconducting rings under magnetic fields using liquid helium. Why are room-temperature superconductors sought after, what did the researchers claim, and why is there scepticism surrounding this announcement?
Why are room-temperature superconductors sought after?
Like fusion power, room-temperature superconductors are a dream that every scientist and engineer desperately wants to come true. Unlike traditional conductors, which have some inherent resistance, a superconductor is a material with zero resistance, meaning that a current that flows through a superconductor never loses energy.
Superconductors are already used in applications that require massive currents and magnetic fields, such as MRI machines, which take advantage of superconducting rings that can maintain a circular current that never dies. Energy can be pumped into these rings, which increases their magnetic field strength, and this is critical for particle physics, where strong magnetic fields can be used to interfere with atomic spin.
However, these superconductors only work at extremely low temperatures, requiring liquid helium to cool them down well below -200˚C. As liquid helium is difficult to produce and in short supply, it is not practical to replace energy grid power lines with helium-cooled conductors, nor is it possible to create semiconductor devices using superconductors. But, if a superconductor can be found to operate at room temperatures (or close), it suddenly becomes possible to transfer energy across vast distances with no losses, create hyper-efficient systems, and significantly reduce the size of power components.
In fact, if a room-temperature superconductor that can be easily manufactured was discovered tomorrow, it would take the world less than a decade to undergo a substantial transformation. It could even be critical in solving the climate crisis issue, having a positive impact on economies and the climate in general.
Researchers claim to have created a superconductor at room temperature
In a paper published in Nature, researchers from the University of Rochester claimed to have found evidence of a superconductor that operates at room temperature. To create the superconductor, the researchers turned to a nitrogen-doped lutetium hydride that was formed under high pressures and temperatures to ensure that the hydrogen impregnated the crystalline structure to create hydrogen-rich compounds. Once formed, the material was held under a pressure of 10kBar, and the resulting material changed in appearance from blue to red. At this pressure, the material was stated to have had superconductive properties even at a temperature of 297K, or around 20˚C.
According to the researchers, the material’s properties were examined along compression pathways to determine the relationship between temperature and resistance depending on the presence of a magnetic field, magnetisation curves, and x-ray diffraction of the crystal structure.
While the resulting material still needs to be held at 10kBar, this pressure is not far from the realms of possibility, as this is the same pressure found at the bottom of the Mariana trench. Thus, it is possible for a strong metallic casing to place the material under pressure, seal the material internally, and then retain the room-temperature superconductive properties. Additionally, the researchers also noted that the importance of their research doesn’t just lie in the high-temperature superconductor but in how temperature and pressure combined affect the formation of hydrogen-rich materials. Thus, future materials may trade off pressure with a lower temperature.
Why are some sceptical over the discovery?
The fact that researchers have discovered a room-temperature superconductor should be enough to justify all newspapers around the world to publish the findings, and yet, the news hasn’t gone as far as many would hope. While there is no sure way of explaining why this is the case, it may be due to the widespread distrust in the researchers who have made the discovery.
According to other researchers, some members involved with the discovery have a long history of research malfeasance. For example, the lead researcher, Dias, had to have a paper published in Nature retracted after it was found that methods used to confirm the results were found to differ from what the paper described. Another researcher also reported how the raw data published by Dias was not raw but instead derived from their own published data. This was proven with the use of mathematics, suggesting that the raw data was fabricated.
“There is a lot of evidence for superconductivity here if you take it at face value. But I do not believe any of what these authors say. I am not sold at all.” - Jorge Hirsch, a physicist at the University of California, San Diego.
Due to the background of the researchers involved, it is difficult to say whether or not a room-temperature superconductor has actually been discovered, and more scrutiny will be needed. However, if the material is indeed a superconductor, it presents engineers with exciting opportunities and will likely improve our understanding of the role of hydrogen in superconductors.