Thermodynamic Properties of New Superconductivity Type I Clathrate Compound Ba_8Si_(46)

摘要

The ground state properties and equation of state of the silicon clathrate Si_(46) intercalated by Ba atoms are investigated by first-principles calculations based on the plane-wave basis set with the generalized gradient approximation (GGA) for exchange and correlation. Some thermodynamic properties including the heat capacity, the thermal expansion coefficient, Debye temperature and the Griineisen parameter for Ba_8Si_(46) are obtained. Moreover, the effects of high pressure on these thermodynamic properties are also investigated which will be very helpful for a synthesis of these clathrates in experiments under high pressure and high temperature condition.