R3: High-pressure science and deep Earth's material

[R3-02] Structures of amorphous hydrous sodium silicates under pressure

「発表賞エントリー」

*Tomonori Ohashi¹, Tatsuya Sakamaki¹, Ken-ichi Funakoshi², Takanori Hattori³, Asami Sano-Furukawa³, Miki Muranushi¹, Chikara Shito⁴, Osamu Ikeda¹, Yoshiaki Ito¹, Yuki Shibazaki⁵, Akio Suzuki¹ (1. Tohoku Univ., Sci., 2. CROSS, 3. JAEA, 4. Univ. Tokyo, Sci., 5. NIMS)

Keywords:silicate melt, water, amorphous structure, high pressure and temperature

Structures of hydrous Na₂O-8/3SiO₂ (NS8/3) melts and dry/deuterated NS8/3 glasses were determined under pressure by the in-situ X-ray diffraction (XRD) and neutron diffraction (ND). The obtained total pair distribution functions indicate different the average Si-O bond lengths (r_Si-O) and their pressure evolutions depending on their water contents. The r_Si-O in the NS8/3 melt (9 wt% H₂O) melt shows the monotonic decrease with increasing pressure, however, the r_Si-O of the NS8/3 melt (5 wt% H₂O) hardly changes at the experimental condition.