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In and , 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 . High pressure usually means pressures of thousands () or millions () oftimes atmospheric pressure (about ).


History and overview
Percy Williams Bridgman received a Nobel Prize in1946 for advancing this area of physics by two magnitudes of pressure ((MPa) to(GPa)). The founders of this field include also Harry George Drickamer, , Francis P. Bundy, , and .

It was by applying high pressure as well as high temperature to 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, (also called or ) will first adopt a denser form known as , then upon application of even higher pressure, form . These two forms of silica were first discovered by high-pressure experimenters, but then found in nature at the site of a .

is liable to change under high pressure, when the term in the free energy becomes comparable to the energies of typical chemical bonds at around . Among the most striking changes are metallization of at (rendering oxygen a ), and transition of from a nearly-free-electron metal to a transparent insulator at. At ultimately high compression, however, all materials will metallize ().

High-pressure experimentation has led to the discovery of the types of minerals which are believed to exist in the of the Earth, such as silicate perovskite, which is thought to make up half of the Earth's bulk, and , which occurs at the core-mantle boundary and explains many anomalies inferred for that region.


Pressure "landmarks"
  • Typical pressures reached by large-volume presses: upto
  • Pressures that can be generated inside diamond anvil cells:
  • Pressure at center of the Earth:
  • Highest pressures ever achieved in : over


See also

Further reading

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