Study of the spin transition in ferropericlase based on X-ray diffraction experiments at ultra-high pressures and high temperatures

2014 Fiscal Year Final Research Report

• Project/Area Number: 24540520
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Petrology/Mineralogy/Science of ore deposit
• Research Institution: University of Hyogo
• Principal Investigator: MATSUI Masanori 兵庫県立大学, 生命理学研究科, 名誉教授 (90125097)
• Co-Investigator(Kenkyū-buntansha): HIGO Yuji 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 (10423435)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 放射光実験 / スピン転移 / 超音波測定 / フェロペリクレイス / 超高圧高温 / 下部マントル

Outline of Final Research Achievements

The elastic wave velocities of (Mg0.8,Fe0.2)O and (Mg0.5,Fe0.5)O ferropericlases have been measured up to 50 GPa, by combining ultrasonic interferometry, in situ synchrotron X-ray diffraction, and X-ray radiographic techniques in a Kawai-type, multi-anvil, high-pressure apparatus and sintered diamond anvils. The sample was heated in a cylindrical TiB2 (+BN) tube, and experimental data were recorded after heating the sample to 1073 K under a fixed press load to minimize non-hydrostatic components due to local deviatoric stresses. The travel times were measured based on the reflections from the sintered diamond cube, the polycrystalline Al2O3 buffer rod, and the sample. An abrupt change in ultrasonic echo from the sample was observed at pressures higher than about 40 GPa in (Mg0.5,Fe0.5)O ferropericlase, suggesting a result of high-spin to low-spin phase transition in the Fe ions.

Free Research Field

固体地球科学