Nav: Home

Scientists discover new properties of uranium compounds

October 15, 2018

Scientists from Russia, China, and the United States predicted and experimentally identified new uranium hydrides, predicting superconductivity for some of them. The results of their study were published in Science Advances.

The phenomenon of superconductivity was discovered in 1911 by a group of scientists led by Dutch physicist Heike Kamerlingh Onnes. Superconductivity means complete disappearance of electrical resistance in a material when it is cooled down to a specific temperature, resulting in the magnetic field being forced out from the material. At the start, superconductivity was discovered in a few base metals, such as aluminum and mercury, at temperatures of several degrees above absolute zero, which is -273° C. Of particular interest to scientists are the so-called "high-temperature superconductors" that boast superconductivity at less extreme temperatures. The highest temperature superconductors are known to date and widely used in electronics operate at -183° C (while the record of high-temperature superconductivity, established in 1993, was -138 °C) and, therefore, need to be constantly cooled. In 2015, a rare sulfur hydride (H3S) set a new high-temperature superconductivity record of -70 °C , although at pressures as high as 1,500,000 atm.

A group of physicists led by Professor of Skoltech and Moscow Institute of Physics and Technology (MIPT) Artem R. Oganov predicted that much lower pressures of about 50,000 atm can produce 14 new uranium hydrides, of which only one, UH3, has been known to date. They include compounds rich in hydrogens, such as UH7 and UH8, that the scientists predicted to be superconducting too. Many of these compounds were then obtained in the experiments conducted by the teams of Professor Alexander Goncharov at the US Carnegie Institution of Washington (USA) and the Institute of Solid State Physics of the Chinese Academy of Sciences. The calculations suggest that the highest-temperature superconductor is UH7 which displays superconducting capability at -219° C - a temperature level that can be increased further by doping.

"After H3S was discovered, scientists started eagerly searching for superconducting hydrides in other non-metals, such as selenium, phosphorus, etc. Our study showed that metal hydrides hold as much potential as non-metals in terms of high-temperature superconductivity," says the main author of the study Ivan Kruglov, a researcher in Computational Materials Discovery Laboratory at MIPT.

"The two highlights of our results are that high pressure produces an amazingly rich collection of hydrides, most of which do not fit into classical chemistry, and that these hydrides can actually be obtained and become superconducting at very low pressures, perhaps even at atmospheric pressure," says Artem Oganov.
-end-


Moscow Institute of Physics and Technology

Related Superconductivity Articles:

Stressing metallic material controls superconductivity
No strain, no gain -- that's the credo for Cornell researchers who have helped find a way to control superconductivity in a metallic material by stressing and deforming it.
First report of superconductivity in a nickel oxide material
Scientists at SLAC and Stanford have made the first nickel oxide material that shows clear signs of superconductivity - the ability to transmit electrical current with no loss.
A hallmark of superconductivity, beyond superconductivity itself
Physicists have found 'electron pairing,' a hallmark feature of superconductivity, at temperatures and energies well above the critical threshold where superconductivity occurs.
Manipulating superconductivity using a 'mechanic' and an 'electrician'
Strongly correlated materials can change their resistivity from infinity to zero with minute changes in conditions.
Triplet superconductivity demonstrated under high pressure
Researchers in France and Japan have demonstrated a theoretical type of unconventional superconductivity in a uranium-based material, according to a study published in the journal Physical Review Letters.
The mechanism of high-temperature superconductivity is found
Russian physicist Viktor Lakhno from Keldysh Institute of Applied Mathematics, RAS considers symmetrical bipolarons as a basis of high-temperature superconductivity.
Superconductivity is heating up
Theory suggests that metallic hydrogen should be a superconductor at room temperature; however, this material has yet to be produced in the lab.
Light pulses provide a new route to enhance superconductivity
Scientists have shown that pulses of light could be used to turn materials into superconductors through an unconventional type of superconductivity known as 'eta pairing.'
Graphene on the way to superconductivity
Scientists at HZB have found evidence that double layers of graphene have a property that may let them conduct current completely without resistance.
New quantum criticality discovered in superconductivity
Using solid state nuclear magnetic resonance (ssNMR) techniques, scientists at the U.S.
More Superconductivity News and Superconductivity Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.