Ranga P. Dias tries to patent the synthesis of his superconducting material at room temperature and low pressure

2023-07-06 12:01:39

The goose that lays golden eggs of superconductivity is a superconducting material at room temperature and pressure. The controversial physicist Ranga P. Dias (Univ. Rochester, NY, USA) announced in March the “possible superconductivity at 294 K and 1 GPa in a nitrogen-doped lutetium hydride” (LCMF, 14 Mar 2023). In July 2022 he applied for an international patent for his method of synthesis of this material; it is not yet approved, but it was made public in April 2023. He claims to synthesize a superconducting material with a critical temperature greater than 250 kelvin for a pressure less than 10 kilobars; This material is composed of hydrogen (H), a rare earth (Ln), which can be lutetium (Lu), ytterbium (Yb) or thulium (Tm), and a dopant (D), which can be nitrogen (N) or boron (B). However, all the figures in the patent present results for LuNH (in fact, the ones he published Nature on March 8, 2023). Does Dias have unpublished results for other materials? Will such a general patent be accepted? No superconductivity expert believes Dias’s results published in NatureWill patent examiners believe the claims of that patent? If the patent were accepted, could it affect the study of superconductivity in doped rare earth hydrides?

All attempts to synthesize the material and replicate Dias’s results have been unsuccessful. The synthesized materials with the properties reported in Nature They do not exhibit high-temperature superconductivity at pressures on the gigapascal scale. None. All the experts believe that Dias’s results are spurious, perhaps the result of a bad electrical contact in the sample for the measurement of its resistivity. To silence the voices against, Dias has given a small instrumentalized sample of his material to Russell J. Hemley (Univ. Illinois, Chicago, USA). His results have been published on arXiv, showing superconductivity up to 280 K with pressures of 15 kbar; this result would confirm those of Dias (294 K at 10 kbar). However, the resistivity vs. temperature curves show (like Dias’s) a transition that is too abrupt to be physical. Also, as Douglas Natelson posts on his blog, Hemley’s results show a strange hysteresis in temperature that suggests a problem with the contacts. Everything indicates that Hemley commits the same experimental errors in his experiments as Dias, which is why he obtains similar results (too far from the norm in this type of experiment to be credible).

By the way, neither Dias nor Hemley have demonstrated the Meissner effect in this material. Still, we all wish there was the goose that lays golden eggs of superconductivity. Unfortunately, no one believes that Dias is the king midas of superconductors. There is a lot of money at stake, so we must not forget the scandal of the Schön case (LCMF, 09 Dec 2017). I am a techno-optimist; For this reason, I believe that we should not lose hope that one day superconducting materials will revolutionize our technological world. The new item (which includes the Excel file with all datausado por Natelson para su figura) es Nilesh P. Salke, Alexander C. Mark, …, Russell J. Hemley, «Evidence for Near Ambient Superconductivity in the Lu-N-H System,» arXiv:2306.06301 [cond-mat.supr-con] (09 Jun 2023), two: https://doi.org/10.48550/arXiv.2306.06301; I recommend reading Douglas Natelson’s short but excellent piece, “A busy and contentious week in condensed matter physics,” Nanoscale Views, 24 Jun 2023. Sobre la patente de Dias recomiendo leer a Robert F. Service, «Embattled physicist files patent for unprecedented ambient superconductor. Little-noticed patent for material that works at room temperature and pressure adds to bevy of sensational but disputed claims,» News, Science, 24 Jun 2023.

As stated in the article by Hemley’s group (Univ. Illinois), Dias’s group (Univ. Rochester) gave them “a synthesized sample prepared for resistance measurements in a diamond anvil cell.” These words suggest that the electrical contacts necessary for resistance measurement were included with the sample; thus any problem with such contacts that explains Dias’s results would also explain Hemley’s results. In my opinion, a non-instrumented sample should have been sent, so that the experimental replication was rigorous. Hemley’s group has not been able to replace the original contacts with their own contacts because the small size of the sample, which could be damaged or destroyed in the process, prevented it.

The agreement between the Hemley and Dias results is excellent. Perhaps too good to be considered a full-fledged replication. All the problems that were documented about the Dias results can also be applied to the Hemley results. In my opinion, everything points to a replication biased by the instrumentalization of the ceded sample. But beyond my untrained opinion, what is a fact is that the superconductivity research community does not buy Hemley’s results, any more than Dias’s. Will Hemley publish his result in a prestigious journal like Nature Physics o Nature Materials? We will have to be aware, but my opinion is that they will not be accepted.