| Project/Area Number |
62460036
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
物性一般（含極低温･固体物性に対する理論）
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| Research Institution | The Research Center for Extreme Materials, Osaka University |
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Principal Investigator |
YAMAGISHI Akio The Research Institute for Extreme Materials, Osaka University, 極限物質研究センター, 助教授 (10006273)
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| Co-Investigator(Kenkyū-buntansha) |
HORI Hidenobu Faculty of Science, Osaka University, 理学部, 助教授 (20028244)
UYEDA Chiaki College of General Education, Osaka University, 教養部, 助手 (50176591)
DATE Muneyuki Faculty of Science, Osaka University, 理学部, 教授 (80028076)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥6,500,000 (Direct Cost: ¥6,500,000)
Fiscal Year 1988: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1987: ¥3,500,000 (Direct Cost: ¥3,500,000)
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| Keywords | liquid oxygen / two-molecule transition / high magnetic field / magneto-volume effect / superconducting magnet / paramagnetic liquid / liquid surface / magnetic fluid / 磁気流体 / 脱色 / 磁気褪色効果 / 磁歪 |
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| Research Abstract |
In this research program, we aided to analyze theoretically and experimentally the dynamic behavior of liquid oxygen under high magnetic field and visually observe the phenomena.
Oxygen is ideal paramagnetic liquid so that it was expected to behave differently under strong magnetic field. We found mainly three magnetic effects: 1) faint blue color of liquid oxygen fades out nonlinearly with applied field intensity, 2) liquid oxygen expands with magnetic field and 3) liquid surface takes sharp cone shape under strong magnetic field.
The absorption of 633 and 577 nm light, shich is a cause of blue color, is due to two molecule transitions ^3sigma_g ^3sigma_g-^1delta_g ^1delta_g. From spin conservation before and agter the transition, the total spin moment of the ground state should be zero. However under an applied magnetic gield, each spins are oriented in the field direction so that the total spin has non-zero value and the transition would be inhibited. This is the outline of the "blue color disappearance". We found "spin-pair model" for liquid oxygen which explains the above phenomenon well. Essential point is that distance of two oxygen molecules interacting is fairly short compared with the other molecules surrounding them and the two molecules makes new states with two spins S=1.
Two oxygen molecules are coupled with antiferromagnetic interaction so that repulsive force elongates the molecular distance when two spins are oriented by magnetic field. This is the origin of the magneto-volume effect. 0.2% increase of volume is observed with 8 T mabnetic field.
The surface shape is determined to have minimum energy. Surface cone shape is due to the balance of surface tension, gravity force and magnetic force. The changing of the surface shape is recorded in video-recorder and photo-pictures.
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