High-pressure dynamic,thermodynamic properties,and hardness of CdP₂

【摘要】 Using a pseudopotential plane-waves method,we calculate the phonon dispersion curves,thermodynamic properties,and hardness values of α-CdP₂ and β-CdP₂ under high pressure.From the studies of the phonon property and enthalpy difference curves,we discuss a phase transform from β-CdP₂ to a-CdP₂ in a pressure range between 20 GPa and 25 GPa.Then,the thermodynamic properties,Debye temperatures,and heat capacities are investigated at high pressures.What is more,we employ a semiempirical method to evaluate the pressure effects on the hardness for these two crystals.The results show that the hardness values of both α-CdP₂ and β-CdP₂ increase as pressure is increased.The influence mechanism of the pressure effect on the hardness of CdP₂ is also briefly discussed.更多还原

【Abstract】 Using a pseudopotential plane-waves method,we calculate the phonon dispersion curves,thermodynamic properties,and hardness values of α-CdP₂ and β-CdP₂ under high pressure.From the studies of the phonon property and enthalpy difference curves,we discuss a phase transform from β-CdP₂ to a-CdP₂ in a pressure range between 20 GPa and 25 GPa.Then,the thermodynamic properties,Debye temperatures,and heat capacities are investigated at high pressures.What is more,we employ a semiempirical method to evaluate the pressure effects on the hardness for these two crystals.The results show that the hardness values of both α-CdP₂ and β-CdP₂ increase as pressure is increased.The influence mechanism of the pressure effect on the hardness of CdP₂ is also briefly discussed.更多还原