The thermal conductivity ofε-iron at high pressure and high temperature is a key parameter to constrain the dynamics and thermal evolution of the Earth’s core.In this work,we use first-principles calculations to stu...The thermal conductivity ofε-iron at high pressure and high temperature is a key parameter to constrain the dynamics and thermal evolution of the Earth’s core.In this work,we use first-principles calculations to study the Hugoniot sound velocity and the thermal transport properties ofε-iron.The total thermal conductivity considering lattice vibration is 200 W/mK at the Earth’s inner core conditions.The suppressed anharmonic interactions can significantly enhance the lattice thermal conductivity under high pressure,and the contribution of the lattice thermal conductivity should not be ignored under the Earth’s core conditions.展开更多
The elastic property and sound velocity of FeaC under high pressure are investigated by using the spin-polarized generalized gradient approximation within density-functional theory. It is found that the magnetic phase...The elastic property and sound velocity of FeaC under high pressure are investigated by using the spin-polarized generalized gradient approximation within density-functional theory. It is found that the magnetic phase transition from the ground ferromagnetic （FM） state to the nonmagnetic （NM） state occurs at ～73 GPa. Based on the predicted Hugoniot of Fe3C, we calculate the sound velocities of FM-Fe3C and NM-Fe3C from elastic constants. Compared with pure iron, NM-FeaC provides a better match of compressional and shear sound velocities with the seismic data of the inner core, supporting carbon as one of the light elements in the inner core.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.12072044)the Natural Science Foundation of Chongqing City(Grant No.cstc2020jcyjmsxmX0616).
文摘The thermal conductivity ofε-iron at high pressure and high temperature is a key parameter to constrain the dynamics and thermal evolution of the Earth’s core.In this work,we use first-principles calculations to study the Hugoniot sound velocity and the thermal transport properties ofε-iron.The total thermal conductivity considering lattice vibration is 200 W/mK at the Earth’s inner core conditions.The suppressed anharmonic interactions can significantly enhance the lattice thermal conductivity under high pressure,and the contribution of the lattice thermal conductivity should not be ignored under the Earth’s core conditions.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.11247316, No.11247317, No.11347019, No.11304408, and No.U1230201）, the Science and Technology Research Project of Chongqing Education Committee （No.K J120613 and No.KJ130607）, and the Natural Science Foundation of Chongqing City （No.cstc2012jjA50019 and No.cstc2013jcyjA0733）.
文摘The elastic property and sound velocity of FeaC under high pressure are investigated by using the spin-polarized generalized gradient approximation within density-functional theory. It is found that the magnetic phase transition from the ground ferromagnetic （FM） state to the nonmagnetic （NM） state occurs at ～73 GPa. Based on the predicted Hugoniot of Fe3C, we calculate the sound velocities of FM-Fe3C and NM-Fe3C from elastic constants. Compared with pure iron, NM-FeaC provides a better match of compressional and shear sound velocities with the seismic data of the inner core, supporting carbon as one of the light elements in the inner core.
