A research team led by Artem Oganov, Professor at Skoltech and MIPT, and Dr Ivan Troyan from the Institute of Crystallography of RAS has successfully synthesized thorium decahydride (ThH10), a novel superconducting material that has an extremely high critical temperature of 161 K.
The study outcomes have been reported in the journal Materials Today. The study was supported by a Russian Science Foundation (RSF) grant.
Superconductivity is a fascinating property of quantum materials, where electrical resistance is completely lost under very specific and, at times, very severe conditions. In spite of the immense potential for high-sensitivity detectors and quantum computers, the use of quantum materials is hampered because superconductivity usually manifests itself at extremely high pressures or extremely low temperatures.
Mercury-containing cuprate had been at the top of the list of superconductors, until recently. This quantum material turns superconducting at 135 K, or −138 °C. Most recently, lanthanum decahydride (LaH10) has set a new record of −13 °С, which is extremely close to room temperature. However, in the case of LaH10, superconductivity is realized only at about 2 million atmospheres, a pressure that can never be achieved in real life.
It is vital to realize superconductivity at pressures and temperatures close to ambient levels. In 2018, a new material—thorium polyhydride (ThH10), with a critical temperature of −32 °С at a pressure of 1 million atmospheres—was proposed by Alexander Kvashnin, a research scientist at the lab directed by Artem R. Oganov, Skoltech and MIPT professor.
In their recent research work, researchers from the Institute of Crystallography of RAS, Skoltech, MIPT, and the Lebedev Institute of Physics of RAS have successfully synthesized ThH10 and analyzed its superconductivity and transport properties.
Their study outcomes were found to be in agreement with the theoretical predictions, demonstrating that ThH10 exists at pressures above 0.85 million atmospheres and exhibits excellent high-temperature superconducting performance.
The researchers were able to establish the critical temperature only at 1.7 million atmospheres, which was found to be −112 °С. This temperature value is in agreement with the theoretical prediction for this pressure value, making ThH10 one of the revolutionary high-temperature superconductors.
Modern theory, and in particular, the USPEX method developed by myself and my students, yet again displayed their amazing predictive power. ThH10 pushes the boundaries of classical chemistry and possesses unique properties that were predicted theoretically and recently confirmed by experiment. Most notably, the experimental results obtained by Ivan Troyan’s lab are of very high quality.
Artem R. Oganov, Study Co-Director and Professor, Skoltech and MIPT
“We discovered that superconductivity predicted in theory does exist at −112 °С and 1.7 million atmospheres. Given the strong consistency between theory and experiment, it would be interesting to check whether ThH10 will show superconductivity at up to −30–40 °C and lower pressures as predicted,” says co-director of the study, Dr Ivan Troyan.
Thorium hydride is just one of the elements in a large and rapidly growing class of hydride superconductors. I believe that in the coming years, hydride superconductivity will expand beyond the cryogenic range to find application in the design of electronic devices.
Dmitry Semenok, Study First Author and PhD student, Skoltech