Hydrogenation of silicon-bearing hexagonal close-packed iron and its implications for density deficits in the inner core

Mori, Yuichiro*; Kagi, Hiroyuki*; Aoki, Katsutoshi*; Takano, Masahiro*; Kakizawa, Sho*; Sano, Asami; Funakoshi, Kenichi*

Earth and Planetary Science Letters, 634, p.118673_1 - 118673_8, 2024/05

https://doi.org/10.1016/j.epsl.2024.118673

To investigate silicon effects on the hydrogen-induced volume expansion of iron, neutron diffraction and X-ray diffraction experiments were conducted to examine hcp-FeSi under high pressures and high temperatures. Neutron diffraction experiments were performed on the deuterated hcp-FeSi at 13.5 GPa and 900 K, and at 12.1 GPa and 300 K. By combining the P-V-T equation of state of hcp-FeSi, present results indicate that the hydrogen-induced volume expansion of hcp-FeSi is 10% greater than that of pure hcp iron. Using the obtained values, we estimated the hydrogen content that would reproduce the density deficit in the inner core, which was 50% less than that without the effect of silicon. Possible hydrogen content, , in the inner core and the outer core was calculated to be 0.07 and 0.12-0.15, respectively, when reproducing the density deficit of the inner core with hcp-FeSiHx.

The Geological characteristics during the quaternary period around Japanese Islands

Hagiwara, Shigeru*; Sakamoto, Yoshiaki; Ogawa, Hiromichi; Nakayama, Shinichi

JAERI-Review 2002-024, 203 Pages, 2002/11

JAERI-Review-2002-024.pdf:15.79MB

Radioactive wastes arising from radioisotope facilities and nuclear research facilities should be disposed of in the surface of the earth, the shallow underground,the adequate depth and the deep undergruond according to radioactivity concentration, and should be managed during several hundreds years. For the selection of disposal site, it is necessary to survey the beginning of earth scientific phenomena observed in the Japanese Islands at present and to reconnoiter the prospective features. This report reviewed on the genesis and classification of sediments, earth scientific phenomena observed in the Japanese Islands and the feature of each place(10 districts) concerning to the Quaternary period in the newest geological time unit.

The Study on selection of secondary minerals formed at bentonite-cement interface, 2; Sensitivity analyses of permeability of bentonite for set of the secondary minerals

Kijima, Tatsuya*; Sasagawa, Tsuyoshi; Sawaguchi, Takuma; Iida, Yoshihisa

no journal, , 

no abstracts in English