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Solid metallic hydrogen has been produced in the laboratory

arxiv.org

41–50 of 65 posts

Re: Solid metallic hydrogen has been produced in the laboratory

#41
post #40

> We used type IIac conic synthetic diamonds (supplied by Almax Easy-Lab) with ~30 micron diameter culet flats. About 5 microns were etched off of the diamond culets using the technique of reactive ion etching, to remove defects from the surface. The diamonds were then vacuum annealed at high temperature to remove residual stress. Alumina is known to act as a diffusion barrier against hydrogen. The diamonds, with the…

Rare that I lough out loud at Hacker News.

Re: Solid metallic hydrogen has been produced in the laboratory

#42
post #40

> We used type IIac conic synthetic diamonds (supplied by Almax Easy-Lab) with ~30 micron diameter culet flats. About 5 microns were etched off of the diamond culets using the technique of reactive ion etching, to remove defects from the surface. The diamonds were then vacuum annealed at high temperature to remove residual stress. Alumina is known to act as a diffusion barrier against hydrogen. The diamonds, with the…

> Photos were taken with a smartphone camera at the ocular of a modified stereo microscope

Still incredible! We as people tend to underestimate just how "magical" our mobile phones are.

Re: Solid metallic hydrogen has been produced in the laboratory

#43
post #26

Someone with a chem/physics background, could you please explain why metallic hydrogen is only theorized to be a superconductor? Is such a property not predictable?

The problem (not having a condensed matter background, so my answer might not be entirely right) is that we can't solve the Schrödinger equation exactly for many-atom systems.

So we need to approximate our solutions to be able to get a good idea of what properties a material will have. Our approximations are pretty good and we have a decent idea of when some things superconductor. But our theories of superconduction aren't yet perfect, and sometimes the approximations can fail//generate behavior unexpected by our theories.

Re: Solid metallic hydrogen has been produced in the laboratory

#44
post #6

Super cool stuff! There are some greatly quotable sentences in the paper: > Moreover, SMH (solid metal hydrogen) is predicted to be metastable so that it may exist at room temperature when the pressure is released. If so, and superconducting, it could have an important impact on mankind’s energy problems and would revolutionize rocketry as a powerful rocket propellant. > The principal limitation for achieving the req…

hell with rocket fuel, if the stuff isn't horribly expensive to produce it could be a good portable source period

Re: Solid metallic hydrogen has been produced in the laboratory

#47

Earlier quoted context omitted.

Metallic Hydrogen can also be a liquid and even a gas, the metallic part indicates it's an electric conductor, not a solid. The "idea" behind metallic hydrogen is that since hydrogen is above the alkali metals in the periodic tables there should be a phase where it behaves like a metal, the state of the phase is not defined as a solid/gas/liquid in fact in all honesty it would exist as all 3 and more. The first produ…

But your parent and grandparent comments are talking about the fact that the authors theorize it may remain metallic once the pressure is released.

Metallic doesn't mean solid, metallic just means it will conduct electricity it will not be solid, or liquid at room temperatures and pressures.

Re: Solid metallic hydrogen has been produced in the laboratory

#48

495GPa... doesn't seem so bad... Standard atmospheric pressure ~= 100Pa So they increased the pressure in that chamber by 4.95billion times. And then they hypothesise that the hydrogen metal could be stable at room temperature. Oh. My. Days.

Standard atmospheric pressure is ~= 100kPa

Re: Solid metallic hydrogen has been produced in the laboratory

#49

Just for reference the pressure at the center of the Earth is estimated to be around 360 GPa, while they are using 495 GPa and DACs able to reach over 700 GPa. https://en.wikipedia.org/wiki/Diamond_anvil_cell

An absolutely silly pressure! For those who might not be familiar, standard steels fail at about 0.5 GPa

Re: Solid metallic hydrogen has been produced in the laboratory

#50
post #6

Super cool stuff! There are some greatly quotable sentences in the paper: > Moreover, SMH (solid metal hydrogen) is predicted to be metastable so that it may exist at room temperature when the pressure is released. If so, and superconducting, it could have an important impact on mankind’s energy problems and would revolutionize rocketry as a powerful rocket propellant. > The principal limitation for achieving the req…

hell with rocket fuel, if the stuff isn't horribly expensive to produce it could be a good portable source period

This makes me wonder, what is the energy density of this stuff? And how easily does it release its energy? (Is it hazardous?)
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