Equation of state (EOS) and collapse of magnetism in Iron-rich meteorites at high pressure by first-principles calculations

J. Nisar (1) , R. Ahuja (1)

1 Department of Physics and Astronomy [Uppsala]

We have calculated electronic and structure properties, equation of state (EOS) and collapse of magnetism of different meteoritic materials at high pressure using density functional theory (DFT). The fully optimization structures are obtained by minimization of the total energy and atomic forces of iron rich materials, which are in good agreement with the experiment. Phase transition of FeP (C22 type structure) barringerite into FeP (C23 type structure) allabogdanite is calculated to be 26GPa. Collapse of magnetism (high spin-low spin) of some iron rich materials are described at various pressures. It has been observed that the optimized equilibrium volume has been changed due to transition of non-magnetic to magnetic material at high pressure, so EOS parameters have also been changed. EOS parameters such as bulk modulus (B) and derivative of bulk modulus with respect to pressure (′) for magnetic and non-magnetic configurations have been calculated by fitting E-V curves with Birch-Murnaghan equation, which confirm the experimental results.

Mots clés: Iron-rich composition; Equation of state; Collapse of magnetism

Domaines: Sciences de la Terre

J. Nisar, R. Ahuja. Equation of state (EOS) and collapse of magnetism in Iron-rich meteorites at high pressure by first-principles calculations. Physics of the Earth and Planetary Interiors, 2010, ⟨10.1016/j.pepi.2010.07.012⟩. ⟨hal-00681623⟩