Arthur T Knackerbracket has found the following story:
The key to this discovery was creation of a metallic, hydrogen-rich compound at very high pressures: roughly 2 million atmospheres. The researchers used diamond anvil cells, devices used to create high pressures, to squeeze together miniscule samples of lanthanum and hydrogen. They then heated the samples and observed major changes in structure. This resulted in a new structure, LaH10, which the researchers previously predicted would be a superconductor at high temperatures.
While keeping the sample at high pressures, the team observed reproducible change in electrical properties. They measured significant drops in resistivity when the sample cooled below 260 K (minus 13 C, or 8 F) at 180-200 gigapascals of pressure, presenting evidence of superconductivity at near-room temperature. In subsequent experiments, the researchers saw the transition occurring at even higher temperatures, up to 280 K. Throughout the experiments, the researchers also used X-ray diffraction to observe the same phenomenon. This was done through a synchrotron beamline of the Advanced Photon Source at Argonne National Laboratory in Argonne, Illinois.
Evidence for Superconductivity above 260 K in Lanthanum Superhydride at Megabar Pressures$ (DOI: 10.1103/PhysRevLett.122.027001)
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A team of French researchers has posted a paper online in which they claim to have achieved the holy grail of extreme-pressure materials science: creating metallic hydrogen in a laboratory.
Physicists have suspected since the 1930s that under extreme pressures, hydrogen atoms — the lightest atoms on the periodic table, containing just a single proton each in the nuclei — might radically change their properties. Under normal circumstances, hydrogen doesn't conduct electricity well and tends to pair with other hydrogen atoms — much like oxygen does. But physicists believe that, subject to enough pressure, hydrogen will act as an alkali metal — a group of elements, including lithium and sodium, that each have a single electron in their outermost orbitals, which they exchange very easily. The whole periodic table is organized around this idea, with hydrogen placed above the other alkali metals in the first column. But the effect has never been conclusively seen in a laboratory.
Now, in a paper posted June 13 to the preprint journal arXiv, a team of researchers led by Paul Loubeyre of the French Atomic Energy Commission claims to have pulled it off. Crushed between the points of two diamonds to about 4.2 million times Earth's atmospheric pressure at sea level (425 gigapascals), they say their sample of hydrogen demonstrated metallic properties.
Also at Gizmodo and ScienceAlert.
Previously: Creation of Jupiter Interior, a Step Towards Room Temperature Superconductivity
Harvard Researchers Report Production and Analysis of Solid Metallic Hydrogen
Solid Metallic Hydrogen, Once Theory, Becomes Reality -- or Maybe Not?
Harvard University's Metallic Hydrogen Sample "Disappeared" or Ruined
Related: New Evidence of Superconductivity at Near Room Temperature
(Score: 2) by bzipitidoo on Wednesday January 16 2019, @07:50PM (6 children)
Sounds great, and very interesting from a theoretical perspective.
However, it doesn't sound immediately useful. Have we got anything that can contain a substance at such high pressures in a small enough package to be practical? Maybe carbon nanotubes? From what I read, they have 63 GPa tensile strength, which is at least within an order of magnitude.
Well, still cool that they managed the high compression needed, and made superconducting LaH10,
(Score: 2) by FatPhil on Wednesday January 16 2019, @09:13PM (4 children)
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 2) by opinionated_science on Wednesday January 16 2019, @11:30PM (3 children)
random thought - what value of acceleration due to gravity on a planet or other celestial body would yield this pressure?
It occurs if chemistry and high pressure is needed, it may occur naturally - although we may never observe the structure!!
(Score: 2) by FatPhil on Thursday January 17 2019, @01:22PM (2 children)
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 2) by opinionated_science on Thursday January 17 2019, @02:03PM (1 child)
's ok that's what I was driving at - "could there be a natural phenomenon that happens to exploit, as yet undiscovered, high-temp superconductors?"
(Score: 0) by Anonymous Coward on Friday January 18 2019, @10:16AM
The issue is, how to dissipate the heat from the compression? To compress the sample using gravity, requires large planetary mass around it. Makes cooling (and else) impractical.
We don't know of any nongravitational natural process able to sustain such pressures.
(Score: 2) by RandomFactor on Thursday January 17 2019, @03:27AM
That was my thought also.
1 atmosphere = 0.0001GPA
Not much use currently, but 100+ GPA might mean we can one day build electronics that work deep inside Jupiter's atmosphere, so there is that.
В «Правде» нет известий, в «Известиях» нет правды
(Score: 2) by stormwyrm on Thursday January 17 2019, @07:39AM
Metallic hydrogen [wikipedia.org] is supposed to behave as a superconductor at temperatures as high as 17°C. Of course, being a form of degenerate matter, it can be made only at extremely high pressures, around 400 GPa at latest theoretical estimate, but as yet no one has made confirmed samples. But if they're seeing what looks like superconductivity at relatively high temperatures in a similar substance like this lanthanum/hydrogen mix, then perhaps metallic hydrogen might indeed be a room temperature superconductor as has been predicted.
Numquam ponenda est pluralitas sine necessitate.