日本地球惑星科学連合2018年大会

講演情報

[EE] ポスター発表

セッション記号 P (宇宙惑星科学) » P-PS 惑星科学

[P-PS03] 太陽系小天体研究:現状の理解と将来の展望

2018年5月23日(水) 10:45 〜 12:15 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:石黒 正晃(ソウル大学物理天文学科)、中本 泰史(東京工業大学)、荒川 政彦(神戸大学大学院理学研究科、共同)、安部 正真(宇宙航空研究開発機構宇宙科学研究所)

[PPS03-P28] Phase relation of MgSO4–H2O system under low temperature and high pressure

*原田 啓多1近藤 忠1白田 実希1亀卦川 卓美2 (1.大阪大学大学院理学研究科宇宙地球科学専攻、2.高エネルギー加速器研究機構)

キーワード:氷天体、高圧、硫酸マグネシウム

In order to estimate the internal structure of icy bodies, we investigated phase transition of MgSO4-H2O system under low temperature and high pressure. A diamond anvil cell was used for high-pressure generation. A low-temperature circulating system and a Peltier device were used for temperature control. The experimental temperature and pressure range were from -40 °C to room temperature and ambient pressure to 5 GPa, respectively. We used 0, 5, 10, 15, 17, 20, and 25 wt% MgSO4 aqueous solutions to evaluate the influence of MgSO4 on the phase diagram of pure H2O.
The pressure was calculated using the ruby fluorescence method. Raman spectroscopy and textural change in the sample room under optical microscope were used for phase identification in laboratory experiments.
To confirm the results of phase identification, we also conducted X-ray diffraction experiments of the solid phases of MgSO4-H2O system up to about 5GPa at room temperature, at NE-1A station, PF-AR, KEK. We identified Ices VI and VII, magnesium pentahydrate, MgSO4・5H2O, Mg(HSO4)2 in the samples at high pressure.
Our results were different from previous study by Ohtani and Nakamura(2011), who identified magnesium heptahydrate, MgSO4・7H2O as the high-pressure phase .
We will report the detailed results of both Raman spectroscopy and X-ray diffraction experiments and possible phase diagram of MgSO4-H2O system and their application to the icy bodies.