2018 Fiscal Year Annual Research Report
Atomic scale diffusion dynamics of hydrogen in deep-Earth minerals by pulsed neutron scattering
Project/Area Number |
17F17331
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Research Institution | Okayama University |
Principal Investigator |
奥地 拓生 岡山大学, 惑星物質研究所, 准教授 (40303599)
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Co-Investigator(Kenkyū-buntansha) |
PUREVJAV NARANGOO 岡山大学, 惑星物質研究所, 外国人特別研究員
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Project Period (FY) |
2017-11-10 – 2020-03-31
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Keywords | hydrous bridgmanite / DHMS phase E |
Outline of Annual Research Achievements |
We synthesized hydrous ringwoodite powder sample of about 400 mg total mass. This sample was subjected for quasielastic neutron scattering measurements at BL-2, Materials and Life Science Experimental Facility, Japan Proton Accelerator Research Complex. The measurements at DNA were intended to observe atomistic-scale diffusion dynamics of hydrogen as a function of temperature occurring within the hydrous ringwoodite structure. We successfully measured the sample at temperatures up to 500 K. Then we synthesized high-quality single crystals of hydrous bridgmanite and dense hydrous magnesium silicate phase E by using scaled-up Kawai-type apparatus at Okayama University. These crystals were subjeced for single crystal neutron diffraction measurements at BL-12 at Spallation Neutron Source, Oak Ridge National Laboratory, USA. The diffraction datasets of these two crystal species were collected with very high resolution in space (dmin as small as 0.5 Angstrom). We are currently analyzing these datasets in depth and preparing for publications. We also made numbers of scientific presentations in several domestic and international meetings to present the results and progress obtained within the last year.
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Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
We have already measured the proposed two important hydrous minerals by single-crystal neutron diffraction. The current data is found to be excellent for refining their hydrogen positions and occupancies in highly quantitative manner.
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Strategy for Future Research Activity |
At the moment, we are analyzing the obtained single crystal neutron diffraction datasets of DHMS phase E. The structure refinement work of DHMS phase E has almost completed and the manuscript writing for the results is now ongoing. Thus it is to be submitted very soon. After that, we will start the manuscript writing for hydrous bridgmanite results. Its preliminary structure refinement has already been made. For the hydrous bridgmanite crystals, we will also conduct transmission electron microscope analysis soon at Kochi Instute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology. We will also attend Japan Geoscience Union 2019 and Japan Association of Mineralogical Sciences 2019 meetings to present and discuss the results of these studies.
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Research Products
(7 results)