JpGU-AGU Joint Meeting 2017

Presentation information

[EE] Oral

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

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

Sun. May 21, 2017 9:00 AM - 10:30 AM A05 (Tokyo Bay Makuhari Hall)

convener:Taku Tsuchiya(Geodynamics Research Center, Ehime University), Hidenori Terasaki(Graduate School of Science, Osaka University), Madhusoodhan Satish-Kumar(Department of Geology, Faculty of Science, Niigata University), Tetsuo Irifune(Geodynamics Research Center, Ehime University), John Hernlund(Earth-Life Science Institute, Tokyo Institute of Technology), Eiji Ohtani(Department of Earth and Planetary Materials Science, Graduate School of Science, Tohoku University), Chairperson:Eiji Ohtani(Department of Earth and Planetary Materials Science, Graduate School of Science, Tohoku University)

9:15 AM - 9:30 AM

[SIT22-26] Newly developed internal-resistive heated diamond-anvil cell with boron-doped diamond: Toward deep lower-mantle petrology

*Shigehiko Tateno1, Haruka Ozawa2,1, Longjian Xie1, Yoichi Nakajima3, Naoya Sakamoto4, Saori Imada5, Akira Yoneda1, Naohisa Hirao5 (1.Institute for Planetary Materials, 2.Laboratory for Advanced Nuclear Energy, 3.Priority Organization for Innovation and Excellence, 4.Creative Research Institution, 5.Japan Synchrotron Radiation Research Institute)

Keywords:DAC, lower mantle

The development of the diamond-anvil cell (DAC) technique combined with laser heating enabled easy access to the entire lower-mantle pressure and temperature regime at laboratory. However, a number of major issues remain highly controversial, including the location of the post-perovskite phase boundary, solid–liquid iron partitioning, Fe–Mg partitioning among mantle minerals, and melting temperatures of mantle rocks. Although the discrepancies between previous experimental studies on these issues have likely arisen from multiple sources, they could more or less have originated from possible problems in the laser-heated diamond-anvil cell (LHDAC) experiment: inherited temperature gradient in the heated area and temperature fluctuation during heating.

In this study, we developed an internal-resistive heated diamond-anvil cell with a new resistance heater—boron-doped diamond (BDD)—along with an optimized design of the cell assembly, including a composite gasket. We find this heating technique to demonstrate clear advantages over the conventional LHDAC technique, such as (1) ultrahigh temperature generation (>3500 K), (2) long-term stability (>1 h at 2500 K), (3) uniform radial temperature distribution (±35 K at 2500 K across a 40-µm area), (4) chemical inertness (no boron diffusion into the silicate sample), and (5) weak X-ray diffraction intensity from the BDD heater. This newly developed IHDAC with a BDD heater can determine the phase diagrams of silicate/oxide materials with high precision and can be used in deep lower-mantle petrology.