Thread Rating:
  • 1 Vote(s) - 1 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Scientists have created metallic hydrogen.
#1
Scientists have created metallic hydrogen. Here's how it could change the world

Metallic Hydrogen

Metallic hydrogen is a potential wonder substance first proposed by Eugene Wigner and Hillard Bell Huntington back in 1935, but since conditions here on Earth are not extreme enough to create it, its existence has remained theoretical — that is, until now.
Harvard scientists Isaac Silvera and Ranga Dias have created metallic hydrogen by squeezing a hydrogen sample with pressures never before produced on Earth, even greater than the pressure that exists at the center of the planet, reports Phys.org.

"This is the holy grail of high-pressure physics," said Silvera. "It's the first-ever sample of metallic hydrogen on Earth, so when you're looking at it, you're looking at something that's never existed before."
They created it using a synthetic diamond that was immaculately polished to remove even the tiniest of imperfections that might weaken it. Since diamond is one of the hardest materials in nature, researchers were able to use it to create pressures greater than 71.7 million pounds-per-square inch, thus transforming solid molecular hydrogen into atomic hydrogen, which is a metal.
This is important because as a metal, hydrogen can function as a superconductor at room temperature. Furthermore, the material is theorized to remain in its metallic state even after the pressure is removed.

"One prediction that's very important is metallic hydrogen is predicted to be meta-stable," explained Silvera. "That means if you take the pressure off, it will stay metallic, similar to the way diamonds form from graphite under intense heat and pressure, but remains a diamond when that pressure and heat is removed."
The work is described in a paper published in the journal Science.
What metallic hydrogen makes possible
It's impossible to understate just how important a stable, room temperature superconductor could be. It could, quite seriously, change the world as we know it. Or at least, it could usher in a new era of technological breakthroughs.

For instance, it would make magnetic levitation for high-speed trains far more feasible, revolutionizing our transportation infrastructure. Electric cars could be made immensely more efficient, and the performance of our electronic devices would be greatly enhanced.
That's just scratching the surface, though. Superconductors have zero resistance, so energy could be stored by maintaining currents in superconducting coils, to be used as needed. Furthermore, since it takes such tremendous pressure to create metallic hydrogen, when it's converted back to molecular hydrogen, all of that energy gets released. In other words, it could potentially create the most powerful rocket propellant known to man, making long-distance space travel more feasible than ever before.
"That would easily allow you to explore the outer planets," Silvera said. "We would be able to put rockets into orbit with only one stage, versus two, and could send up larger payloads, so it could be very important."

Researchers still have some work to do before these technologies can be realized, however. First and foremost, they need to test to make sure that the properties of theoretical metallic hydrogen match up with the properties of the real thing. It's still a remarkable accomplishment either way.
"It's a tremendous achievement, and even if it only exists in this diamond anvil cell at high pressure, it's a very fundamental and transformative discovery," said Silvera.
Seek and ye shall find. JESUS
------------------------------------------
I am a recovering vegetarian   Hi
Reply
#2
Quote:But all bets are off... Arrow Naughty  Gamble with

Earth's inhabitants need to keep in mind as they consider long-term space travel.

"With the recent discovery of multiple exoplanets, we're reminded of the vastness of the universe," he says. "Our understanding of chemistry has to change and expand beyond the confines of our own planet."

Elementals react differently in ANU World Order

Up, up and away: Chemists say 'yes,' [Image: avatar_191.jpg?dateline=1429792715] helium can form compounds
February 6, 2017 by Mary-Ann Muffoletto

[Image: upupandawayc.jpg]
Representation of chemical bonding analysis of the Na2He structure via the SSAdNDP method: 8c-2e bond is found inside of every empty Na8 cube. For clarity, only two such bonds are shown. Credit: Ivan Popov, Utah State University


Can helium bond with other elements to form a stable compound? Students attentive to Utah State University professor Alex Boldyrev's introductory chemistry lectures would immediately respond "no." And they'd be correct – if the scholars are standing on the Earth's surface.



But all bets are off, if the students journey to the center of the Earth, à la Jules Verne's Otto Lidenbrock or if they venture to one of the solar system's large planets, such as Jupiter or Saturn.
"That's because extremely high pressure, like that found at the Earth's core or giant neighbors, completely alters helium's chemistry," says Boldyrev, faculty member in USU's Department of Chemistry and Biochemistry.
It's a surprising finding, he says, because, on Earth, helium is a chemically inert and unreactive compound that eschews connections with other elements and compounds. The first of the noble gases, helium features an extremely stable, closed-shell electronic configuration, leaving no openings for connections.
Further, Boldyrev's colleagues confirmed computationally and experimentally that sodium, never an earthly comrade to helium, readily bonds with the standoffish gas under high pressure to form the curious Na2He compound. These findings were so unexpected, Boldyrev says, that he and colleagues struggled for more than two years to convince science reviewers and editors to publish their results.
Persistence paid off. Boldyrev and his doctoral student Ivan Popov, as members of an international research group led by Artem Oganov of Stony Brook University, published the pioneering findings in the Feb. 6, 2017, issue of Nature Chemistry.
[Image: 1-upupandawayc.jpg]
Chemical bonding analysis of the Na2He structure via the SSAdNDP method: Ball-and-stick representation, left, and polyhedral representation, right, where half of the Na8 cubes are occupied by He atoms (shown as polyhedra) and haf by two electrons (shown as red spheres). Pink and gray atoms represent Na and He, respectively. Credit: Ivan Popov, Utah State University

Additional authors on the paper include researchers from China's Nankai University, Center for High Pressure Science and Technology, Chinese Academy of Sciences, Northwestern Polytechnical University, Xi'an and Nanjing University; Russia's Skolkovo Institute of Science and Technology, Moscow Institute of Physics and Technology, Sobolev Institute of Geology and Mineralogy and RUDN University; the Carnegie Institution of Washington, Lawrence Livermore National Laboratory, Italy's University of Milan, the University of Chicago and Germany's Aachen University and Photo Science DESY.

Boldyrev and Popov's role in the project was to interpret a chemical bonding in the computational model developed by Oganov and the experimental results generated by Carnegie's Alexander Goncharov. Initially, the Na2He compound was found to consist of Na8 cubes, of which half were occupied by helium atoms and half were empty.
"Yet, when we performed chemical bonding analysis of these structures, we found each 'empty' cube actually contained an eight-center, two-electron bond," Boldyrev says. "This bond is what's responsible for the stability of this enchanting compound."
Their findings advanced the research to another step.
[Image: 8-scientistsdi.jpg]
Crystal structure of Na2He, resembling a three-dimensional checkerboard. The purple spheres represent sodium atoms, which are inside the green cubes that represent helium atoms. The red regions inside voids of the structure show areas where localized electron pairs reside. Credit: Artem R. Oganov

"As we explore the structure of this compound, we're deciphering how this bond occurs and we predicted that, adding oxygen, we could create a similar compound," Popov says.
Such knowledge raises big questions about chemistry and how elements behave beyond the world we know. Questions, Boldyrev says, Earth's inhabitants need to keep in mind as they consider long-term space travel.
"With the recent discovery of multiple exoplanets, we're reminded of the vastness of the universe," he says. "Our understanding of chemistry has to change and expand beyond the confines of our own planet."

[Image: 1x1.gif] Explore further: Scientists discover extraordinary compounds that may be hidden inside Jupiter and Neptune
More information: A stable compound of helium and sodium at high pressure, Nature ChemistryDOI: 10.1038/nchem.2716 
Journal reference: Nature Chemistry [Image: img-dot.gif] [Image: img-dot.gif]
Provided by: Utah State University



Read more at: https://phys.org/news/2017-02-team-stabl...s.html#jCp[/url][url=https://phys.org/news/2017-02-team-stable-helium-compounds.html#jCp]
Along the vines of the Vineyard.
With a forked tongue the snake singsss...
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)