論文

査読有り
2015年

Crystal structure, equation of state, and elasticity of phase H(MgSiO4H2) at Earth's lower mantle pressures

Scientific Reports
  • Jun Tsuchiya
  • ,
  • Mainak Mookherjee

5
記述言語
掲載種別
研究論文(学術雑誌)
DOI
10.1038/srep15534

Dense hydrous magnesium silicate (DHMS) phases play a crucial role in transporting water in to the Earth's interior. A newly discovered DHMS, phase H (MgSiO4H2), is stable at Earth's lower mantle, i.e., at pressures greater than 30 GPa. Here we report the crystal structure and elasticity of phase H and its evolution upon compression. Using first principles simulations, we have explored the relative energetics of the candidate crystal structures with ordered and disordered configurations of magnesium and silicon atoms in the octahedral sites. At conditions relevant to Earth's lower mantle, it is likely that phase H is able to incorporate a significant amount of aluminum, which may enhance the thermodynamic stability of phase H. The sound wave velocities of phase H are ∼2-4% smaller than those of isostructural δ-AlOOH. The shear wave impedance contrast due to the transformation of phase D to a mixture of phase H and stishovite at pressures relevant to the upper part of the lower mantle could partly explain the geophysical observations. The calculated elastic wave velocities and anisotropies indicate that phase H can be a source of significant seismic anisotropy in the lower mantle.

リンク情報
DOI
https://doi.org/10.1038/srep15534
Scopus Url
http://www.scopus.com/inward/record.url?eid=2-s2.0-84945285076&partnerID=MN8TOARS
URL
http://www.scopus.com/inward/record.url?partnerID=HzOxMe3b&scp=84945285076&origin=inward
ID情報
  • DOI : 10.1038/srep15534
  • ORCIDのPut Code : 49519604
  • SCOPUS ID : 84945285076

エクスポート
BibTeX RIS