Metallic Hydrogen

  • Thread starter Orion1
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  • #1
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Metallic Hydrogen:

Metallic hydrogen was first created - at Livermore in 1996 - in the liquid state at relatively high temperature. Whether solid metallic hydrogen can be created, however, remains unclear so far. According to early calculations, solid hydrogen should start conducting at about 340 GPa. The compression of solid hydrogen to 342 GPa at Cornell University in 1998 failed to produce the metallic phase, however. Now experiments by P Loubeyre and colleagues in France may help develop a more accurate theoretical model and identify conditions necessary for solid metallic hydrogen to form. The team used Raman spectroscopy to obtain a detailed absorption spectrum of solid hydrogen at pressures up to 320 GPa. It is found that as pressure increases from 290 GPA to 320 GPa, the sample changes its color from white through yellow and red to black. Of particular importance is the discovery at a pressure above 300 GPa of an energy gap characteristic of semiconductors. As pressure is increased to 320 GPa, the gap narrows. Extrapolation shows that at 450 GPa the gap should disappear, turning solid hydrogen to a (metallic) conductor.

Reference:
http://www.nature.com
 

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  • #2
LURCH
Science Advisor
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Haven't had a chance to read the artical yet; Orion, did they say anything about whether these new insiths help predict if metalic Hydrogen can be a stable solid under normal everyday conditions? That was one of the big unnanswered questions last time I had info.
 
  • #3
970
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METALLIC HYDROGEN HAS BEEN ACHIEVED at Livermore in a sample of fluid hydrogen. William Nellis at Livermore was somewhat surprised when he succeeded at lesser pressures with fluid hydrogen. He used a gas gun to compress samples of liquid H2 and D2. Able to make direct electrical measurements on his 1- inch-wide sample (unlike the anvil experiments---with their micron- sized samples---which can only use indirect optical probes), he observed that the sample's resistivity fell with increasing pressure, leveling off at a low value (comparable to that of the fluid alkali metals Cs and Rb under similar conditions) at pressures above 1.4 Mbar, about a million times Earth's atmospheric pressure.

Reference:
http://www.aip.org/enews/physnews/1996/split/pnu263-1.htm [Broken]
http://www.llnl.gov/str/Nellis.html


Metallic Hydrogen is currently only stable under pressure.
 
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  • #4
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this has been round for years. but does anyone acually know what'll be like if it was stable at 1 bar?

light and strong? light and weak? brittle? soft?
 
  • #5
970
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Metal Metallica...



Some data pulled from the internet, indeterminate accuracy, accurate enough for some calculations.

Metallic Hydrogen Properties: (paired metal)
Electronic energy band gap: 15 eV - uncompressed insulator
Electronic energy band gap: 0.3 eV - Metal @ 4000º K and 1.4 Mega-atmospheres (Matm)
Electrical Resistivity: ~0 ohm*m - Type II Superconductor @ 4000º K and 1.4 Mega-atmospheres (Matm)
Standard Density: 2696.487 kg*m^-3 (2.696 g*cc^-1)
Metallic Density: 24268.3899 kg*m^-3 @ 4000º K (24.268 g*cc^-1)
Tensile Strength: ~40-50 kg*mm^-2 @ 4000º K
Propellant Efficiency: 5*liquid H2/O2

 
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  • #6
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Buh.... o_O

can i have that in english? ^__^
 
  • #7
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Originally posted by Gara
Buh.... o_O

can i have that in english? ^__^

I second that! I don't feel like Googling a bunch of various metals and comparing each and every property, could someone who already has that knowledge please enlighten us as to the possible practical uses for such a metal? Thx!
 
  • #8
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I know i have seen a phase diagram for Hydrogen. And according to the Thermodynamics Hydrogen cannot exsist as metal at 1 bar. I'll see if I can find it in my texts and journals and scan it in.
 
  • #9
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so urm.... if it can be a solid metalic metal at 1 bar @ room temp, would it be a super light super strong material?

its proberly a dumb question but wouldnt it be basicly a block of fuel, like charcoal blocks?

"Throw another block of solid metalic hydrogen on the barbeque, lets get this thing started!"
 

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