A miracle material that can easily conduct electricity at room temperature could transform civilization, reclaim energy lost through electrical resistance and open up the possibility of new technologies.
However, claims about this room-temperature superconductor, published in the prestigious journal Nature in March, have raised questions, with some even suspecting that the result was fabricated.
But now, a team of researchers at the University of Illinois at Chicago reports that they have verified a key measurement: the apparent disappearance of electrical resistance.
The result doesn’t prove that the material is a room-temperature superconductor, but it may prompt other scientists to take a closer look.
Ranga P. Dias, a professor of mechanical engineering and physics at the University of Rochester in New York and a key figure in the original research, reported that the material appears to be a superconductor at temperatures of 70 degrees Fahrenheit — a temperature much higher than that of much higher. Compared to other superconductors, when squeezed under a pressure of 145,000 pounds per square inch, that’s about 10 times the pressure at the bottom of the ocean’s deepest trenches.
The high pressure means the material is unlikely to find practical use, but if the discovery is true, it could point the way to other superconductors that actually work under everyday conditions.
This claim has been met with skepticism as some scientific controversy has swirled around Dr Dias, while other scientists who have tried to replicate the results have failed to find any signs of superconductivity.
Dr. Dias founded a company called Unearthly Materials to commercialize the research and has raised $16.5 million in funding from investors to date.
The new measurements were published in preprint paper The research, released this month, comes from a team led by Russell J. Hemley, professor of physics and chemistry at the University of Illinois at Chicago. Dr Hemley declined to comment because the paper had not yet been accepted by a scientific journal.
Still, he is well-known in the field, and his report may lead to a more positive reconsideration of Dr Dias’ claims of superconductivity.
“That might convince some people,” said James J. Hamlin, a professor of physics at the University of Florida who has been critical of Dr. Diaz’s research. “It made me think there might be some truth to it.”
Dr Dias’ material is made of lutetium, a silvery-white rare-earth metal, along with hydrogen and small amounts of nitrogen. Using a sample provided by Dr Dias, Dr Hemley’s lab made independent measurements of the material’s electrical resistance when cooled under high pressure.
Dr Heimley and his colleagues observed a dramatic drop in the material’s electrical resistance. Although these occur at temperatures as high as 37 degrees Fahrenheit, about 30 degrees lower than what Dr. Dias described, but still warm compared to other superconductors. The transition temperature varies depending on how tightly the material is extruded.
“They performed resistance measurements to confirm our results,” Dr. Dias said in an interview. “It does show a dependence of the transition temperature on pressure, which fits very well with our paper published in Nature in March.”
Dr Hemley’s measurements did not provide evidence of superconductivity. It’s possible that the material is just a very good conductor, not a superconductor.
The report did not include measurements to determine whether there was a zero magnetic field inside. This phenomenon, known as the Meissner effect, is considered clear evidence for the existence of superconductors.
Some of Dr. Dias’s early papers sparked intense debate. Critics, including Dr. Hamlin, say key details about how experimental data are processed are sometimes missed.journal Nature even retracted a paper The study, published in 2020, made earlier claims of superconductors, despite objections from Dr Dias and other authors, who say the findings are still valid.
Dr. Hamlin also noted that Dr. Diaz’s extensive research 2013 Washington State University Doctoral Dissertation yes copyAlmost verbatim from the work of other scientists, including Dr. Hamlin’s own doctoral dissertation.
Dr Dias admitted he had copied the work of others in the paper and said he should have included citations. He denies scientific misconduct in his earlier papers.
“I have never knowingly or knowingly participated in any practice of plagiarizing anyone’s scientific work,” Dr. Dias said. “It was an oversight.”
The results of Dr Hemley’s team show that Dr Dias has indeed discovered something new in the lutetium-hydrogen-nitrogen material.
Lilia Boeri, a professor of physics at the University of Rome I, said it was clear that this was not a repeat of the scientific scandal two decades ago, when J. Hendrik Schön, a researcher at Bell Laboratories in New Jersey, made up his data, claiming a series of groundbreaking discoveries.
“It’s a whole different story, in the sense that he did create something and measure something,” Dr. Boeri said of Dr. Dias.
But, she adds, “it’s not clear whether this indicates superconductivity, or just that he found some type of interesting electron transport.”
In recent years, materials known as hydrides have proven promising in the search for superconductors that operate at higher temperatures, although so far they have all required crushing pressure. Dr Dias said it was the hydride that led him to discover the lutetium-hydrogen-nitrogen mixture.
However, Dr. Boeri said that while other hydrides fit the standard theory of superconductivity, Dr. Dias’ substance did not.
an earlier paperDr. Hemley, Adam Denchfield, a graduate student in physics at the University of Illinois at Chicago, and Hyowon Park, an assistant professor of physics at the same university, tried to explain why, saying researchers had overlooked subtleties in electronics. The structure of lutetium hydrogen nitrogen compounds can explain the higher superconducting temperature.
They propose that the elements in Dr Dias’ material can be configured into different structures. The most prevalent structures may cause color changes and other observed properties, while superconducting current flows through the small number of different structures in the compound. This could explain why not all samples, or even those created in Dr. Dias’ lab, are superconducting.
But Dr. Boeri is unwavering.
“The theoretical arguments are totally weird,” she said. A material with a high superconducting temperature, at least according to conventional theory, would require a very rigid lattice structure, which this material does not have, Dr. Boeri said, an issue not discussed in the paper.
Eva Zurek, a professor of chemistry at the University at Buffalo who has collaborated with Dr. Hemley and Dr. Dias on other projects, was initially skeptical but has now partly changed her mind.
Numerical simulations of superconductors include computational simplifications. Dr. Hemley’s thesis argued that the calculations should be performed differently, and when Dr. Zurek’s team tried these modifications, they arrived at the same answer.
“I realized it wasn’t impossible,” Dr. Zurek said. “I wouldn’t immediately rule that out, let’s just say it.”