Equation of state for aluminum in warm dense matter regime**Project supported by the National Natural Science Foundation of China (Grant No. 51807050), the National Basic Research Program of China (Grant No. 2015CB251002) and the Program for the Top Young and Middle-aged Innovative Talents of Higher Learning Institutions of Hebei, China (Grant No. BJ2017038).

Abstract

A semi-empirical equation of state model for aluminum in a warm dense matter regime is constructed. The equation of state, which is subdivided into a cold term, thermal contributions of ions and electrons, covers a broad range of phase diagram from solid state to plasma state. The cold term and thermal contribution of ions are from the Bushman–Lomonosov model, in which several undetermined parameters are fitted based on equation of state theories and specific experimental data. The Thomas–Fermi–Kirzhnits model is employed to estimate the thermal contribution of electrons. Some practical modifications are introduced to the Thomas–Fermi–Kirzhnits model to improve the prediction of the equation of state model. Theoretical calculation of thermodynamic parameters, including phase diagram, curves of isothermal compression at ambient temperature, melting, and Hugoniot, are analyzed and compared with relevant experimental data and other theoretical evaluations.