| Autor: |
Tetsuo Irifune, Takaya Nagai, Matthew L. Whitaker, Toru Shinmei, Kiyoshi Fujino, Yasuhiro Kuwayama, Daisuke Nishio-Hamane, Hiroaki Ohfuji, Yusuke Seto |
| Rok vydání: |
2014 |
| Předmět: |
|
| Zdroj: |
Physics of the Earth and Planetary Interiors. 228:186-191 |
| ISSN: |
0031-9201 |
| DOI: |
10.1016/j.pepi.2013.12.008 |
| Popis: |
Spin transition and substitution of Fe3+ in Fe3+AlO3-bearing MgSiO3 perovskite (Pv) and post-perovskite (PPv) were examined up to 200 and 165 GPa, respectively, at room temperature by X-ray emission spectroscopy (XES) and XRD. The results of XES and XRD indicate that in Pv high spin (HS) Fe3+ at the dodecahedral (A) site replaces Al at the octahedral (B) site and becomes low spin (LS) between 50 and 70 GPa with pressure, while in PPv LS Fe3+ occupies the B-site and Al occupies the A-site above 80–100 GPa. The Fe3+–Al coupled substitution seems to be at work in both Pv and PPv. Combining these results on Fe3+ with the recent first-principles calculations on Fe2+ in Pv and PPv, the spin transition and substitution of iron in pyrolitic lower mantle minerals are proposed. Further, their effects on iron-partitioning among the lower mantle minerals are discussed. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect