In this paper the elastic and thermodynamic properties of the cubic zinc-blende structure BeS at different pressures and temperatures are investigated by using ab initio plane-wave pseudopotential density functional t...In this paper the elastic and thermodynamic properties of the cubic zinc-blende structure BeS at different pressures and temperatures are investigated by using ab initio plane-wave pseudopotential density functional theory method within the generalized gradient approximation （GGA）. The calculated results are in excellent agreement with the available experimental data and other theoretical results. It is found that the zinc-blende structure BeS should be unstable above 60GPa. The thermodynamic properties of the zinc-blende structure BeS are predicted by using the quasi-harmonic Debye model. The pressure-volume-temperature （P - V - T） relationship, the variations of the thermal expansion coefficient α and the heat capacity Cv with pressure P and temperature T, as well as the Gruneisen parameter-pressure-temperature （γ- P - T） relationship are obtained systematically in the ranges of 0-90GPa and 0-2000K.展开更多
An equation of state(EOS) is a thermodynamic equation describing the state of matter under a given set of physical conditions,and the Mie-Grüneisen EOS is a widely used EOS for solid materials.Polyimide is a typi...An equation of state(EOS) is a thermodynamic equation describing the state of matter under a given set of physical conditions,and the Mie-Grüneisen EOS is a widely used EOS for solid materials.Polyimide is a typical complex high-molecular polymer of imide monomers which is widely used in the manufacture of parts for aerospace technology and for fabricating the inertial fusion energy shells(IFE).When a spacecraft collides with a meteoroids(or orbital debris) or the IFE shells are radiated by high power laser,the polyimide used in the equipment is in high pressure state.In order to study the safety of the spacecraft and IFE shells,the EOS of polyimide should be determined.In our research,the three key parameters of the Mie-Grüneisen EOS based on the shock adiabat for polyimide have been determined with two-stage light-gas gun experiments,i.e.the bulk speed of sound of polyimide is determined as 2.62±0.22 km/s,the linear Hugoniot slope coefficient is determined as 1.25±0.063,and the Grüneisen parameter at initial state is determined as 1.53±0.135.The Mie-Grüneisen EOS for polyimide is finally obtained,and the parameter values are proved reliable via the comparison of Grüneisen parameter value calculated from two different theoretical models using the experimental data.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No 10576020)the NSAF (Grant No 10776022)
文摘In this paper the elastic and thermodynamic properties of the cubic zinc-blende structure BeS at different pressures and temperatures are investigated by using ab initio plane-wave pseudopotential density functional theory method within the generalized gradient approximation （GGA）. The calculated results are in excellent agreement with the available experimental data and other theoretical results. It is found that the zinc-blende structure BeS should be unstable above 60GPa. The thermodynamic properties of the zinc-blende structure BeS are predicted by using the quasi-harmonic Debye model. The pressure-volume-temperature （P - V - T） relationship, the variations of the thermal expansion coefficient α and the heat capacity Cv with pressure P and temperature T, as well as the Gruneisen parameter-pressure-temperature （γ- P - T） relationship are obtained systematically in the ranges of 0-90GPa and 0-2000K.
基金supported by the National Natural Science Foundation of China (11002162 and 10672180)
文摘An equation of state(EOS) is a thermodynamic equation describing the state of matter under a given set of physical conditions,and the Mie-Grüneisen EOS is a widely used EOS for solid materials.Polyimide is a typical complex high-molecular polymer of imide monomers which is widely used in the manufacture of parts for aerospace technology and for fabricating the inertial fusion energy shells(IFE).When a spacecraft collides with a meteoroids(or orbital debris) or the IFE shells are radiated by high power laser,the polyimide used in the equipment is in high pressure state.In order to study the safety of the spacecraft and IFE shells,the EOS of polyimide should be determined.In our research,the three key parameters of the Mie-Grüneisen EOS based on the shock adiabat for polyimide have been determined with two-stage light-gas gun experiments,i.e.the bulk speed of sound of polyimide is determined as 2.62±0.22 km/s,the linear Hugoniot slope coefficient is determined as 1.25±0.063,and the Grüneisen parameter at initial state is determined as 1.53±0.135.The Mie-Grüneisen EOS for polyimide is finally obtained,and the parameter values are proved reliable via the comparison of Grüneisen parameter value calculated from two different theoretical models using the experimental data.
