1992 Fiscal Year Final Research Report Summary
RESEARCH ON HELIUM 3 IN MICROSCOPIC GEOMETRY
| Project/Area Number |
03640343
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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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 | OKAYAMA UNIVERSITY OF SCIENCE |
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Principal Investigator |
FUJII Yoshiko OKAYAMA UNIVERSITY OF SCIENCE DEPARTMENT OF APPLIED PHYSICS ASSOCIATE PROFESSOR, 理学部, 助教授 (20159122)
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| Co-Investigator(Kenkyū-buntansha) |
SHIGI Toyoichiro OKAYAMA UNIVERSITY OF SCIENCE DEPARTMENT OF APPLIED PHYSICS PROFESSOR, 理学部, 教授 (80046747)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Liquid helium 3 / Size effect / Wall effect / Fermi temperature / Paramagnon |
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| Research Abstract |
The influence of dimensionality and of finite size on magnetism, specific heat, superfluidity, statics or other properties is of fundamental importance in physics. We have measured the specific heat of liquid <@D13@>D1He in a restricted geometry. The sample is produced by shooting <@D13@>D1He ions into Ag foils and annealing the foils, which results in <@D13@>D1He gas bubbles of diameter about 100 A. The <@D13@>D1He liquifies when the metal foils are cooled to low temperatures. We have measured the thermal relaxation time of the foils at 13 mK (] SY.ltorsim.[) T (] SY.ltorsim.[) 1.2 K, and have determined the specific heat of the <@D13@>D1He bubbles ; it differs from the specific heat of bulk liquid <@D13@>D1He. Our data indicate that the second layer of <@D13@>D1He on a Ag substrate shows a constant specific heat. This mean that the Fermi temperature of this two-dimensional liquid has to be T<@D2F@>D2 < 40 mK, pointing to a very strong enhancement of the magnetic interactions of the <@D13@>D1He close to the Ag substrate. Another sample of liquid <@D13@>D1He in a restricted geometry is produced as follows ; the <@D14@>D1He containing 0.9 atm % <@D13@>D1He is pressurized up to 32 bar and cooled, which results in <@D13@>D1He droplets in the hcp <@D14@>D1He below about 70 mK. The specific heat data show that only a part of the separated <@D13@>D1He is liquified and the behavior of the liquid <@D13@>D1He is similar to the bulk liquid <@D13@>D1He in contrast with the <@D13@>D1He droplets in Ag substrate.
In order to clarify the behavior of the second layer of ^3He on substrate, we are carrying on a specific heat measurements of liquid ^3He in a restricted geometry produced by sintering the very fine (100 A) Pt powders at millikelvin temperatures.
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