Japan Geoscience Union Meeting 2018

Presentation information

[EE] Poster

S (Solid Earth Sciences) » S-IT Science of the Earth's Interior & Tectonophysics

[S-IT22] Interaction and Coevolution of the Core and Mantle in the Earth and Planets

Tue. May 22, 2018 10:45 AM - 12:15 PM Poster Hall (International Exhibition Hall7, Makuhari Messe)

convener:Tsuyoshi Iizuka(University of Tokyo), Hidetoshi Shibuya(Department of Earth and Environmental Sciences, Faculty of Advanced Science and Technology, Kumamoto University), Taku Tsuchiya(愛媛大学地球深部ダイナミクス研究センター, 共同), Kenji Ohta(Department of Earth and Planetary Sciences, Tokyo Institute of Technology)

[SIT22-P03] Phase relations in the Fe-Ni-Si system at high pressures and high temperatures

*Daijo Ikuta1, Eiji Ohtani1 (1.Department of Earth Science, Tohoku University)

Keywords:Fe-Ni-Si system, phase relation, high pressure

The Earth's core has supposed to be constituted by iron-nickel alloys with some light elements. Silicon is one of the most convincing candidates among the light elements. Therefore, the study of high pressure and high temperature properties and behaviors for the Fi-Ni-Si system is important in understanding and constraining to the properties of the Earth's core. In this study, high pressure and high temperature properties for three different contents of Fe-Ni-Si alloys were investigated by using laser heated diamond anvil cells and in situ X-ray diffraction with synchrotron radiation. We determined the phase relations of Fe(0.94-x)Ni0.06Six (x = 0.10, 0.17, 0.26) up to 125 GPa and 2800 K, respectively. According to previous Fe-Si system studies, Fe0.83Si0.17 alloys transform from hcp to hcp+B2 and fcc+hcp+B2 phases with increasing temperature in isobaric conditions. We observed the change in temperature increase and positive slope of these boundaries due to the nickel containing effect and the difference in silicon content. We report the details of phase relations in the Fe-Ni-Si system and discuss with the differences from the Fe-Si system.