Metallic Hydrogen: Learn About This Rare Substance

[gravenewworld]

Never heard of it until I stumbled upon an article about it today. Interesting stuff. Here is a page about it:

https://www.llnl.gov/str/Nellis.html

 

[GCT]

Yep "hydrides" right?

 

[gravenewworld]

Yep "hydrides" right?

Nope. It is when hydrogen is placed under an immense amount of pressure (something like 5 million atmpospheres), you get a different allotrope of hydrogen that behaves more like a metal (like being able to conduct electricity). Hydrogen is above the rest of the alkali metals, so why can't it behave like the rest of them?
It sounds like really neat stuff.

 

[~christina~]

Nope. It is when hydrogen is placed under an immense amount of pressure (something like 5 million atmpospheres), you get a different allotrope of hydrogen that behaves more like a metal (like being able to conduct electricity).

Hydrogen is above the rest of the alkali metals, so why can't it behave like the rest of them?

It sounds like really neat stuff.

holy cow...5 million atmospheres?!

interesting how it turns into liquid metal
wonder how it looks...

 

[LtStorm]

Yeah, metallic hydrogen is really neat. Hopefully one day we'll figure out how to stabilize it so it can exist outside massive pressures... I think it was considered as an explosive, as well.

interesting how it turns into liquid metal
wonder how it looks...

I'd guess it'd look like the other alkali metals.

 

[grandunifier]

SiH4

They've found a novel way to Metallic hydrogen, in prestressed lattices of SiH4, something to do with a novel LASER approach to making it.

much easier than gas guns.

 

[mgb_phys]

It's thought to be the source of Jupiter's large magnetic field. The core of Jupiter is very probably metallic hydrogen.

 

[Gokul43201]

Hydrogen is above the rest of the alkali metals, so why can't it behave like the rest of them?

This is not the reason that hydrogen "can" be metallized. In theory, any non-metal will lose its band gap at some sufficiently high pressure, and become a conductor.

They've found a novel way to Metallic hydrogen, in prestressed lattices of SiH4, something to do with a novel LASER approach to making it.

much easier than gas guns.

Do you have a reference?

 

[grandunifier]

Superconductivity in SiH4 attributed to Metallic Hydrogen

Supercompressed silicon and hydrogen superconducts at room temperature

A new superconducting material fabricated by a Canadian-German team has been fabricated out of a silicon-hydrogen compound [after supercompression, 96-120GPa] and does not require cooling.

Abstract. A combination of static and dynamical first-principles electronic calculations of silane, SiH4, at high pressure has revealed a novel monoclinic structure with C2/c symmetry. This high-pressure phase is metallic and composed of layers of SiH4 bridged by H bonds. Perturbative linear response calculations at 90 and 125 GPa predict large electron-phonon couplings yielding an electron-phonon coupling parameter λ close to 0.9. The application of McMillan equation gives a superconducting critical temperature (Tc) between 45 and 55 K.

"In other words the Superconductivity observed in SiH4 is attributed to a metallic hydrogen phase shift internally", grandunifier.

"If you put hydrogen compounds under enough pressure, you can get superconductivity," said professor John Tse of the University of Saskatchewan. "These new superconductors can be operated at higher temperatures, perhaps without a refrigerant."

He performed the theoretical work with doctoral candidate Yansun Yao. The experimental confirmation was performed by researcher Mikhail Eremets at the Max Plank Institute in Germany.

The new family of superconductors are based on a hydrogen compound called "silane," which is the silicon analog of methane--combining a single silicon atom with four hydrogen atoms to form a molecular hydride. (Methane is a single carbon atom with four hydrogens).

Researchers have speculated for years that hydrogen under enough pressure would superconduct at room temperature, but have been unable to achieve the necessary conditions (hydrogen is the most difficult element to compress). The Canadian and German researchers attributed their success to adding hydrogen to a compound with silicon that reduced the amount of compression needed to achieve superconductivity.

I can dig up more references- if you need em, but this will get you started.

 

[Gokul43201]

grandunifier, what you posted above is an (unreferenced) excerpt. I was hoping for a citation to a peer-reviewed paper. A citation looks something like this:

J. Feng, et al. Structures and Potential Superconductivity in SiH4 at High Pressure:
En Route to ‘‘Metallic Hydrogen’’ Physical Review Letters, v. 96, p. 017006 (2006)

If you only have a url to a news article, then you will have to break it up some to get past our spam filter. Thanks for the excerpt.

 

[Redbelly98]

Hydrogen is above the rest of the alkali metals, so why can't it behave like the rest of them?

I guess if you want hydrogen's outer electron free to participate in conduction, that wouldn't leave very many left over to help bind the nuclei together into a rigid lattice.

 

[Fearless]

I thought that metallic hydrogen formed with 25 GPa? somewhat 250000 atm? Or am I wrong?

 

[grandunifier]

It does inside the atomic lattice, the term "pre-stressed" refers to this process whereas the hydrogen atoms are in a state of hyper-compression, and then after a forced phase shift to a metallic state occurs when the laser compression technique is applied. Afterwards the hydrogen is kept in a metallic state within the SiH4 lattice without outside compression.

I studied the many theoretical ways to make this material, and found that trying to use normal materials to contain it like a vessel wouldn't work, even titanium was only half as strong as it needed to be to make a "gas exchange" cylinder for this material. Being formed within a latticework is quite unique and possible very useful as superconductors like rigid busbars for nuclear plants that can go to high temps, as one possibility.

This means we could make "things" out of this material and test it's energy interfaces, I'd love to see a full report on reactions to everything from electron guns to radiations, but I'm sure some upper grad student would have to take an interest in this material first, but it would make a great thesis for them.

I surely would buy a book written on this material as long as it had cool glossy sem pics, lots of diagrams and a hot chick on the cover, lol.

There are predicted interactions with metallic hydrogen which go beyond normal uses, there are special interactions which I have seen predictions for. I can't wait to be able to buy some.