Physics:High pressure

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Short description: Great force distributed over a small area

In science and engineering, the study of high pressure examines its effects on materials and the design and construction of devices, such as a diamond anvil cell, which can create high pressure. High pressure usually means pressures of thousands (kilobars) or millions (megabars) of times atmospheric pressure (about 1 bar or 100 kilopascals).

History and overview

Percy Williams Bridgman received a Nobel Prize in 1946 for advancing this area of physics by two magnitudes of pressure (400 megapascals (MPa) to 40 gigapascals (GPa)). The founders of this field include also Harry George Drickamer, Tracy Hall, Francis P. Bundy, Leonid F. Vereschagin (ru), and Sergey M. Stishov (ru).

It was by applying high pressure as well as high temperature to carbon that synthetic diamonds were first produced alongside many other interesting discoveries. Almost any material when subjected to high pressure will compact itself into a denser form; for example, quartz (also called silica or silicon dioxide) will first adopt a denser form known as coesite, then upon application of even higher pressure, form stishovite. These two forms of silica were first discovered by high-pressure experimenters, but then found in nature at the site of a meteor impact.

Chemical bonding is liable to change under high pressure, when the P * V term in the free energy becomes comparable to the energies of typical chemical bonds at around 100 GPa. Among the most striking changes are metallization of oxygen at 96 GPa (rendering oxygen a superconductor), and transition of sodium from a nearly-free-electron metal to a transparent insulator at ≈ 200 GPa. At ultimately high compression, however, all materials will metallize (see metallization pressure).‍[1]


Pressure "landmarks"

  • Typical pressures reached by large-volume presses: up to 30–40 GPa
  • Pressures that can be generated inside diamond anvil cells: ≈ 1000 GPa[2]
  • Pressure at center of the Earth: 364 GPa
  • Highest pressures ever achieved in shock waves: over 100 terapascals (100,000 GPa)‍[3]

See also

References

  1. Grochala, Wojciech; Hoffmann, Roald; Feng, Ji; Ashcroft, Neil W. (4 May 2007). "The Chemical Imagination at Work in Very Tight Places". Angewandte Chemie International Edition (Wiley-VCH) 46 (20): 3620–3642. doi:10.1002/anie.200602485. CODEN ACIEF5. ISSN 1433-7851. PMID 17477335. 
  2. Dubrovinskaia, Natalia; Dubrovinsky, Leonid; Solopova, Natalia A.; Abakumov, Artem; Turner, Stuart; Hanfland, Michael; Bykova, Elena; Bykov, Maxim et al. (20 July 2016). "Terapascal static pressure generation with ultrahigh yield strength nanodiamond". Science Advances (American Association for the Advancement of Science) 2 (7). doi:10.1126/sciadv.1600341. ISSN 2375-2548. OCLC 892343396. PMID 27453944. Bibcode2016SciA....2E0341D. 
  3. Jeanloz, Raymond; Celliers, Peter M.; Collins, Gilbert W.; Eggert, Jon H.; Lee, Kanani K. M.; McWilliams, R. Stewart; Brygoo, Stéphanie; Loubeyre, Paul (29 May 2007). "Achieving high-density states through shock-wave loading of precompressed samples". Proceedings of the National Academy of Sciences 104 (22): 9172–9177. doi:10.1073/pnas.0608170104. CODEN PNASA6. ISSN 0027-8424. OCLC 43473694. PMID 17494771. Bibcode2007PNAS..104.9172J. 

Further reading