Modeling of shock wave loading FeO to 1000 GPa

Iron oxide, FeO, is one of the main rock-forming oxides. Research into its thermophysical properties under high-energy loading is necessary to construct an equation of state that is used in modeling the properties of Earth's mantle and core as well as other celestial bodies. The results of calculations of thermodynamic properties of FeO under shock compression up to 1000 GPa are presented. In the phase transition field, calculations for FeO are performed as a mixture of low- and high-pressure phases based on the assumption that components of the mixture are in thermodynamic equilibrium under shock wave loadings. The conditions at the wave front are expressed in Rankin–Hugoniot ratios that express conservation of mass, momentum, and energy. Conservation conditions for momentum and energy flow are written for the mixture overall, while conservation conditions for mass flow are written separately for each component. Supplementing the obtained expressions with the condition of equality of the component temperature values and the equations of state for each component, shock adiabatic curves for a heterogeneous material are obtained. This method allows us to accurately describe the shock-wave loading of FeO, including in the phase transition region. Verification of simulation results is carried out using data obtained from experiments and calculations by other researchers. The considered technique is useful for calculations of similarly complex materials.