High Pressure

Equations of State

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Figure 1: Preparation of a sample for loading in a diamond anvil cell. The sample is placed at the center of diamond culet with two needles.

Equations of State

The equation of state P(V,T) or V(P,T) (P pressure, V specific volume, T temperature) is a fundamental characteristic of a material and describes how the forces within the material evolve when its atomic and electronic structure changes. This level of description is specifically required for planets and stars, where high pressures and high temperatures prevail. In the laboratory, we measure and compute the equations of state of elements and compounds under extreme conditions. Experimentally, our favorite tools are laser-heated diamond anvil cells, synchrotron radiation and laser-shock processing – we are thus active users of several large instruments. Theoretically, we perform molecular dynamic simulations using the density functional theory or numerical potentials – we develop several computational codes and take advantage of our large access to supercomputers located nearby.

High pressure-temperature equation of state of beryllium measured using X-ray diffraction in laser-heated diamond anvil cell. Taken from Lazicki et al., Phys. Rev. B 86, 174118,2012

Figure 2:

High pressure-temperature equation of state of beryllium measured using X-ray diffraction in laser-heated diamond anvil cell. Taken from Lazicki et al., Phys. Rev. B 86, 174118,2012

Publications

  1. S. Anzellini, F. Bottin, J. Bouchet, A. Dewaele, Phase transitions and equation of state of zirconium under high pressure, Phys. Rev. B 102, 184105 (2020) DOI
  2. P. Lafourcade, C. Denoual, and J.-B. Maillet, Mesoscopic constitutive law with nonlinear elasticity and phase transformation for the twinning-buckling of TATB under dynamic loading, Phys. Rev. Materials 3, 053610 (2019) DOI
  3. A. Dewaele, P. Loubeyre, F. Occelli, O. Marie and M. Mezouar, Toroidal diamond anvil cell for detailed measurements under extreme static pressures, Nat. Comm. 9, 2913 (2018) DOI
  4. B. Amadon and B. Dorado, A unified and efficient theory for the structural properties of actinides and phases of plutonium, J. Phys.: Condens. Matt. 30, 405603 (2018) DOI
  5. T. Plisson, N. Pineau, G. Weck, E. Bruneton, N. Guignot, and P. Loubeyre, Equation of state of 1,3,5-triamino-2,4,6-trinitrobenzene up to 66 GPa, J. Appl. Phys. 122, 235901 (2017) DOI

Researchers involved

B. Amadon, R. Béjaud, F. Bottin, C. Denoual, A. Dewaele, A. Forestier, F. Gendron, G. Geneste, P. Lafourcade, P. Loubeyre, J.-B. Maillet, P. Lafourcade, F. Occelli, C. Pépin, N. Pineau, V. Recoules, B. Siberchicot, A. Sollier, L. Soulard, L. Toraille, M. Torrent, L. Videau, G. Weck