Equation of state fits to the lower mantle and outer core

We report the high-pressure synthesis and the equation of state (EOS) of a novel nickel carbide (Ni3C). It was synthesized in a diamond anvil cell at 184(5) GPa through a direct reaction of a nickel powder with carbon from the diamond anvils upon heating at 3500 (200) K. Ni3C has the cementite-type structure (Pnma space group, a = 4.519(2) Å, b = 5.801(2) Å, c = 4.009(3) Å), which was solved and refined based on in-situ synchrotron single-crystal X-ray diffraction. The pressure-volume data of Ni3C was obtained on decompression at room temperature and fitted to the 3rd order Burch-Murnaghan equation of state with the following parameters: V0 = 147.7(8) Å3, K0 = 157(10) GPa, and K0' = 7.8(6). Our results contribute to the understanding of the phase composition and properties of Earth’s outer core.

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1S0 Pairing Gaps, Chemical Potentials and Entrainment Matrix in Superfluid Neutron-Star Cores for the Brussels–Montreal Functionals

Universe ◽

10.3390/universe7120470 ◽

2021 ◽

Vol 7 (12) ◽

pp. 470

Author(s):

Valentin Allard ◽

Nicolas Chamel

Keyword(s):

Neutron Star ◽

Equation Of State ◽

Neutron Stars ◽

Physical Meaning ◽

Outer Core ◽

Time Dependent ◽

Hartree Fock ◽

Chemical Potentials ◽

Bogoliubov Equations ◽

Flow Velocities

Temperature and velocity-dependent 1S0 pairing gaps, chemical potentials and entrainment matrix in dense homogeneous neutron–proton superfluid mixtures constituting the outer core of neutron stars, are determined fully self-consistently by solving numerically the time-dependent Hartree–Fock–Bogoliubov equations over the whole range of temperatures and flow velocities for which superfluidity can exist. Calculations have been made for npeμ in beta-equilibrium using the Brussels–Montreal functional BSk24. The accuracy of various approximations is assessed and the physical meaning of the different velocities and momentum densities appearing in the theory is clarified. Together with the unified equation of state published earlier, the present results provide consistent microscopic inputs for modeling superfluid neutron-star cores.

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3. Minerals and the interior of the Earth

10.1093/actrade/9780199682843.003.0003 ◽

2014 ◽

Author(s):

David Vaughan

Keyword(s):

Upper Mantle ◽

Lower Mantle ◽

Plate Tectonics ◽

Inner Core ◽

Indirect Evidence ◽

Outer Core ◽

The Earth ◽

Granite Formation ◽

Temperature And Pressure

‘Minerals and the interior of the Earth’ looks at the role of minerals in plate tectonics during the processes of crystallization and melting. The size and range of minerals formed are dependent on the temperature and pressure of the magma during its movement through the crust. The evolution of the continental crust also involves granite formation and processes of metamorphism. Our understanding of the interior of the Earth is based on indirect evidence, mainly the study of earthquake waves. The Earth consists of concentric shells: a solid inner core; liquid outer core; a solid mantle divided into a lower mantle, a transition zone, and an upper mantle; and then the outer rigid lithosphere.

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Computation for Equation of States of (Mg0.92, Fe0.08)SiO3 Perovskite Based on Mie-Grüneisen-Debye Model

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1046.76 ◽

2014 ◽

Vol 1046 ◽

pp. 76-79

Author(s):

Xiu Fang Chen

Keyword(s):

High Pressure ◽

Equation Of State ◽

Lower Mantle ◽

Perovskite Structure ◽

Perovskite Phase ◽

Debye Model ◽

Thermal Pressure ◽

Thermal Equation ◽

Equation Of States ◽

Prem Model

In this paper, the thermal equation of state (EOS) of (Mg0.92, Fe0.08)SiO3is computed by Birch-Murnaghan and Mie-Grüneisen-Debye equations and the related parameters are also analyzed. The value of and has little effect on EOS of (Mg0.92, Fe0.08)SiO3perovskite. The effect of EOS of (Mg0.92, Fe0.08)SiO3perovskite is mainly from the temperature under high pressure. The temperature is higher; the deviation of EOS relative to the PREM model is bigger. The thermal EOS complies with PREM model at T=2000K. The thermal pressure of (Mg0.92, Fe0.08)SiO3perovskite a constant only related to temperature at the lower mantle conditions. At the same time, the EOS of (Mg0.92, Fe0.08)SiO3perovskite is insensitive to the data of and at T=2000K, but when and the thermal EOS is more agreement with PREM model. That is to say, when the value of the and is in the range of 253~273 GPa and 3.69~4.23, (Mg0.92, Fe0.08)SiO3is the perovskite phase, and (Mg0.92, Fe0.08)SiO3perovskite structure remains stable at the mantle conditions.

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