Abstract:
Periclase (MgO) is one of the important materials that make up the mantles of the terrestrial planets. In this regard, its properties at high temperatures and pressures reflect the nature of the planetary interior. Numerical modeling of shock wave loading of MgO taking into account the polymorphic phase transition in a pressure range of 325 $\div$ 400 GPa was carried out using a thermodynamic equilibrium model. The parameters of the consistent equation of state for the high and low pressure phases of periclase (MgO I and MgO II) are determined. The thermodynamic parameters of these phases were modeled. Shock adiabats of single and double compression were constructed in the range 1 $\div$ 1000 GPa, the values of heat capacity along the normal isobar, entropy as a function of temperature, and temperature along the shock adiabat were calculated. The modeling results were verified based on the results of experiments and calculations of other authors.
Keywords:equation of state of matter, phase transition, magnesium silicates, periclase.
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