Phase relations of iron-light elements alloys at high pressure and high temperature

2010 Fiscal Year Final Research Report

• Project/Area Number: 21840037
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Petrology/Mineralogy/Science of ore deposit
• Research Institution: Ehime University
• Principal Investigator: KUWAYAMA Yasuhiro Ehime University, 地球深部ダイナミクス研究センター, 助教 (00554015)
• Project Period (FY): 2009 – 2010
• Keywords: 超高圧 / 地球中心核 / 相平衡 / 鉄合金

Research Abstract

I have largely improved the data quality of in-situ x-ray diffraction measurements at multimegabar pressures and high temperatures. As a result, I succeeded in determining the crystal structures of pure iron and iron-nickel alloy at the pressure and temperature condition of the Earth's inner-core based on reliable data. I determined a solubility of silicon, which is thought to be the most likely candidate of the light element in the Earth's core, into solid iron at high pressures and temperatures and showed that silicon may be contained not only in the Earth's liquid outer-core, but also in the solid inner-core. I also discovered a new ultra-high pressure phase transitions in metal dioxides at multimegabar pressures during this technical development.

Research Products

• [Journal Article] Pressure-induced structural evolution of pyrite-type SiO2 (2011)
  • Author(s): Kuwayama Y, Hirose, K., Sata, N., Ohishi, Y.
  • Journal Title: Physics and Chemistry of Minerals in press
  • Peer Reviewed
• [Journal Article] 超高圧下における鉄合金の相平衡と地球中心核の構造 (2010)
  • Author(s): 桑山靖弘
  • Journal Title: 20 Pages: 65-71
  • Peer Reviewed
• [Journal Article] Phase relations of iron-silicon alloys at high pressure and high temperature (2009)
  • Author(s): Kuwayama Y, Sawai, T., Hirose, K., Sata, N., Ohishi, Y.
  • Journal Title: Physics and Chemistry of Minerals 36(9) Pages: 511-518,doi:10.1007/s00269-009-0296-0
  • Peer Reviewed
• [Presentation] Crystal structure of iron-rich iron-alloys under the Earth's core conditions. (2010)
  • Author(s): 桑山靖弘
  • Organizer: American Geophysical Union Fall Meeting 2010
  • Place of Presentation: San Francisco, CA, USA
  • Year and Date: 2010-12-16
• [Presentation] P-V-T equation of state of MgSiO3 perovskite up to 110 GPa and 2500 K : Primary reference for the mineralogy of the lower mantle. (2010)
  • Author(s): Tange, Y., Kuwayama Y, Irifune, T., Funakoshi, K., Ohishi, Y.
  • Organizer: American Geophysical Union Fall Meeting 2010
  • Place of Presentation: San Francisco, CA, USA
  • Year and Date: 2010-12-16
• [Presentation] P-V-T equation of state of MgSiO3 perovskite up to 110 GPa and 2500 K : Primary reference for the mineralogy of the lower mantle. (2010)
  • Author(s): Tange, Y., Kuwayama Y, Irifune, T., et al.
  • Organizer: The 2010 TANDEM Symposium on deep Earth mineralogy
  • Place of Presentation: Wuhan, China
  • Year and Date: 2010-11-06
• [Presentation] Effect of silicon on the equation of state and crystal chemistry of hcp iron up to 150 GPa and 2500K (2009)
  • Author(s): Shahar, A., Fei, Y., Ricolleau A., Kuwayama Y
  • Organizer: American Geophysical Union Fall Meeting 2009
  • Place of Presentation: San Francisco, CA, USA
  • Year and Date: 20091200
• [Presentation] Phase relations of iron alloys at high pressure (2009)
  • Author(s): Kuwayama Y, Hirose, K., Sata, N., Ohishi, Y.
  • Organizer: American Geophysical Union Fall Meeting 2009
  • Place of Presentation: San Francisco, CA, USA
  • Year and Date: 20091200
• [Presentation] Jamieson Award (AIRAPT) Lecture (2009)
  • Author(s): 桑山靖弘
  • Organizer: Laser-Heated Diamond-Anvil Cell Experiments at Multimegabar Pressure, AIRAPT-22
  • Place of Presentation: 東京お台場
  • Year and Date: 20090700