Simultaneous sound velocity and density measurements of hcp iron up to 93 GPa and 1100 K: An experimental test of the Birch's law at high temperature

Daniele Antonangeli (1) , Tetsuya Komabayashi (2) , Florent Occelli (3) , Elena Borissenko (4) , Guillaume Fiquet (1) , Yingwei Fei (5) , Andrew C. Walters (4)

1 IMPMC - Institut de minéralogie et de physique des milieux condensés
2 Department of Earth and Planetary Sciences [TITECH Tokyo]
3 DAM/DIF - DAM Île-de-France
4 ESRF - European Synchrotron Radiation Facility
5 Geophysical Laboratory [Carnegie Institution]

We performed sound velocity and density measurements on polycrystalline hexagonal close-packed (hcp) iron at simultaneous high pressure and high temperature, up to 93 GPa and 1100 K, by inelastic x-ray scattering and x-ray diffraction. Our experimental results indicate that high-temperature anharmonic corrections are negligible at least up to 1100 K and that the aggregate compressional velocity VP scales linearly with density over the pressure and temperature range of the investigation (Birch's law). The new results are compared with literature studies and we discuss the extrapolation schemes commonly used in experimental mineral physics, with specific regard to extrapolations to the Earth's core conditions

Mots clés: inner core; hcp iron; sound velocity; high pressure and high temperature; inelastic x-ray scattering

Domaines: Minéralogie

Daniele Antonangeli, Tetsuya Komabayashi, Florent Occelli, Elena Borissenko, Guillaume Fiquet, et al.. Simultaneous sound velocity and density measurements of hcp iron up to 93 GPa and 1100 K: An experimental test of the Birch's law at high temperature. Earth and Planetary Science Letters, 2012, 331, pp.210-214. ⟨10.1016/j.epsl.2012.03.024⟩. ⟨hal-00689919⟩