High-pressure study of hydrogen in iron: implication for the Earth's core

2014 Fiscal Year Final Research Report

• Project/Area Number: 25871243
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Petrology/Mineralogy/Economic geology; Solid earth and planetary physics
• Research Institution: Japan Synchrotron Radiation Research Institute
• Principal Investigator: HIRAO Naohisa 公益財団法人高輝度光科学研究センター, 利用研究促進部門, 研究員 (70374915)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 地球核 / 高温高圧 / 鉄水素化物

Outline of Final Research Achievements

Hydrogen in the Earth's core is believed to have a key role in the structure and dynamics of Earth's core. However, the behavior of hydrogen in the core and its abundance remain an open question. For the purpose of elucidate the crystal structure, phase relation, and properties of iron-hydrogen system under high-pressure and high-temperature conditions corresponding to the Earth's core, we have upgraded and established high-pressure and high-temperature in-situ powder X-ray diffraction techniques for metal-hydrogen system. A structural phase transition into a new high-pressure phase was confirmed above 85 GPa and 1500 K. Because the abundance of hydrogen in the Earth's core was based on prossible stability of double-hexagonal-close-packed structure under the Earth's core conditions, the discovery of the new phase gives a new model for hydrogen in the Earth's core.

Free Research Field

高圧地球惑星科学