Equation of state of solids from high-pressure isotherm

A new variant of the method of finding the equation of state in the Mie–Grüneisen form is presented. It is based only on high-pressure isotherms of solids. Using this procedure, the semiempirical equation of state and shock adiabats of solids may be found at high pressures and high temperatures. The method is tested on periclase MgO within the range of shock pressures up to 300–500 GPa.     

Effect of shock-wave compression up to 65 GPa on the crystal structure and superconducting properties of MgB<Subscript>2</Subscript>

The effect of steplike shock-wave compression up to 65 GPa on the crystal structure and super-conducting transition temperature of a polycrystalline MgB₂ sample is studied. X-ray diffraction demonstrates that the shock-wave compression of the MgB₂ sample does not cause any irreversible structural phase transformations in it except for the formation of lattice microstrains. These conclusions agree with the super-conducting transition temperatures of the MgB₂ sample measured before and after shock-wave compression.     

Electrical conductivity and equations of states of β-rhombohedral boron in the megabar dynamic pressure range

The pressure dependence of the conductivity of boron under conditions of a stepwise shock compression of megabaric range is studied. With this purpose, the following problems have been solved. The conductivity of boron has been measured in the range of dynamic pressures, where boron has different high-pressure phases. The equations of state of β-rhombohedral and amorphous boron have been constructed in a megabaric pressure range. The thermodynamic states of boron in the conditions of these experiments are calculated, which, in combination with the measurement data, made it possible to determine the change in the boron conductivity in the conditions of strong stepwise shock compression at dynamic pressures to 110 GPa. The increase in the conductivity of polycrystalline boron at megabar pressures is interpreted as a result of a nonmetal–metal transition.

     

Estimation of the Critical Point Parameters of the Liquid–Vapor Phase Transition of Metals Using Experiments on the Isentropic Expansion of Shock-Compressed Porous Samples

Journal of Experimental and Theoretical Physics - The isentropic expansion of shock-compressed porous metals (Cu, W, Nb) are experimentally studied, and the experimental results are used to...     

Quasi-isentropic compression of C60H36 hydrofullerene and the evaluation of its thermodynamic properties at high pressures

Physicomechanical properties of the C₆₀H₃₆ hydrofullerene have been investigated in the course of quasi-isentropic compression up to 30 GPa in shock anvils. Experimental information on the variation in the velocity of the back anvil surface during loading of the sample has been obtained using a laser velocimeter. An equation of state of the hydrofullerene has been constructed, and the inference has been made that the wave resistance of the hydrofullerene at high pressures is high. It has been noted that the viscosity effects manifest themselves during shock compression of the hydrofullerene.