Thermodynamic Studies on Magnetic Properties of Nano-Scaled Magnets
| Project/Area Number |
14540534
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
機能・物性・材料
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| Research Institution | Osaka University |
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Principal Investigator |
MIYAZAKI Yuji Osaka University, Graduate School of Science, Research Associate, 大学院・理学研究科, 助手 (70252575)
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| Project Period (FY) |
2002 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2005: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2004: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2003: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2002: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | Nano-Scaled Magnet / Superparamagnetism / Magnetic Quantum Tunneling / Single-Molecule Magnet / Single-Chain Magnet / Heat Capacity / Magnetic Entropy / 強磁性相転移 / 超微細分裂 / 反強磁性相互作用 / ブロッキング温度 / モノレイヤーナノクラスター / 強磁性相互作用 |
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| Research Abstract |
Nano-scaled Magnets have been attracting much attention because of not only application such as a new magnetic memory but also academic aspects such as superparamagnetism, magnetic quantum tunneling, and so on. There are two strategies for development of nano-scaled magnets : top-down type and bottom-up type. In this research, I have investigated specific magnetic properties of bottom-up types of the single-molecule magnet [Mn_<12>O_<12>(O_2CPh) _<16>(H_2O)_4] and the single-chain magnet [Mn(saltmen)] _2[Ni(pao)_2(py)_2](ClO_4)_2 and a top-down type of Ni(OH)_2 monolayered nanocluster (Ni-MNC) in amorphous SiO_2.
It was revealed by the magnetic-field dependence of the heat capacity of the [Mn_<12>O_<12>(O_2CPh)_<16>(H_2O)_4] crystal that the crystal has a magnetic-field-direction-dependence for the heat capacity and that the heat capacity data can be accounted for well by the spin Hamiltonian for an S=10 spin system with a uniaxial anisotropy. The magnetic-field dependence of the heat capacity of the [Mn(saltmen)]_2[Ni(pao)_2(py)_2](ClO_4)_2 crystal indicated the nature of a one-dimensional antiferromagnet. It was suggested by the magnetic-field dependence of the heat capacity of the Ni-MNC that ferromagnetic interactions exist in the Ni-MNC and among the Ni-MNCs. It was concluded by the estimated magnetic entropy that a broad magnetic thermal anomaly is due to the magnetic ordering of the Ni^<2+> cations with S=1.
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Report
(5 results)
Research Products
(25 results)
