Thermodynamic Studies on Magnetic Properties of Nano-Scaled Magnets

纳米磁体磁性能的热力学研究

• 批准号: 14540534
• 负责人: MIYAZAKI Yuji
• 金额: $ 1.86万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540534/
• 关键词: 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

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.

纳米磁性材料不仅具有新型磁存储器等应用价值，而且在超顺磁性、磁量子隧穿等学术领域也有着广泛的应用前景，目前纳米磁性材料的发展有两种策略：自上而下型和自下而上型。本论文研究了自下而上型单分子磁体[Mn_<12>O_<12>（O_2CPh）_<16>（H_2O）_4]和单链磁体[Mn（saltmen）] _2[Ni（pao）_2（py）_2]（ClO_4）_2以及自上而下型Ni（OH）_2单层纳米团簇（Ni-MNC）在非晶SiO_2中的特殊磁性。<12><12><16>的热容量的依赖性和热容量的数据可以很好地占自旋哈密顿量为S=10自旋系统的单轴各向异性。[Mn（saltmen）]_2[Ni（pao）_2（py）_2]（ClO_4）_2晶体的热容随磁场的变化表明其为一维反铁磁体。这是由磁场依赖的Ni-MNC的热容量，铁磁相互作用存在于Ni-MNC和Ni-MNC之间。通过估算的磁熵可以得出结论，广泛的磁热异常是由于S=1的Ni^&lt;2+&gt;阳离子的磁有序化。

项目成果

Molecular rotor of Cs2([18]crown-6)3 in the solid state coupled with the magnetism of [Ni(dmit)2]

• DOI: 10.1021/ja043527a
• 发表时间: 2005-03-30
• 期刊: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
• 影响因子: 15
• 作者: Akutagawa, T;Shitagami, K;Saito, K
• 通讯作者: Saito, K

Calorimetric investigation of phase transitions in the layered antiferromagnetic molecule-based material {N(n-C_5H_<11>)_4[Mn^<II>Fe^<II>(ox)_3]}_∞(ox=oxalato)

层状反铁磁分子材料{N(n-C_5H_<11>)_4[Mn^<II>Fe^<II>(ox)_3]}_∞(ox=草酸根)相变的量热研究

• 发表时间: 2004
• 期刊: J.Magn.Magn.Mater. 280・1
• 作者: M.Sorai;M.Sorai;M.Sorai;Y.Miyazaki;Y.Miyazaki;Y.Miyazaki;Y.Miyazaki;Y.Miyazaki;Y.Miyazaki;T.Akutagawa;S.Ikeuchi;B.Sieklucka;A.Bhattacharjee
• 通讯作者: A.Bhattacharjee

Low-Temperature Heat Capacity and One-Dimensional Ferromagnetic Behavior of the Organic Free Radical 4-Benzylidenamino-2,2,6,6-…

有机自由基4-亚苄基氨基-2,2,6,6-…的低温热容和一维铁磁行为

• 发表时间: 2002
• 期刊: J. Phys. Chem. B 106・25
• 作者: M.Sorai;M.Sorai;M.Sorai;Y.Miyazaki;Y.Miyazaki;Y.Miyazaki;Y.Miyazaki;Y.Miyazaki;Y.Miyazaki;T.Akutagawa;S.Ikeuchi;B.Sieklucka;A.Bhattacharjee;T.Hashiguchi;T.Hashiguchi;T.Sakakibara
• 通讯作者: T.Sakakibara

Heat capacity and magnetic phase transition of two-dimensional metal-assembled complex, K[{MnIII(3-MeOsalen)}2FeIII(CN)6]

二维金属组装复合物 K[{MnIII(3-MeOsalen)}2FeIII(CN)6] 的热容和磁相变

• DOI: 10.1016/j.tca.2005.01.059
• 发表时间: 2005
• 期刊: Thermochimica Acta
• 影响因子: 3.5
• 作者: Y. Miyazaki;Qi Wang;Qing;T. Matsumoto;H. Miyasaka;N. Matsumoto;M. Sorai
• 通讯作者: M. Sorai

Heat capacities of quasi-two-dimensional hetero-spin honeycomb magnets {NBu_4[Cu^<II>Cr^<III>(ox)_3]}_n and {PPh_4[Mn^<II>Cr^<III>(ox)_3]}_n…

准二维异质自旋蜂窝磁体{NBu_4[Cu^<II>Cr^<III>(ox)_3]}_n和{PPh_4[Mn^<II>Cr^<III>(ox)的热容_3]}_n…

• 发表时间: 2003
• 期刊: J. Chem. Phys. 119・13
• 作者: M.Sorai;M.Sorai;M.Sorai;Y.Miyazaki;Y.Miyazaki;Y.Miyazaki;Y.Miyazaki;Y.Miyazaki;Y.Miyazaki;T.Akutagawa;S.Ikeuchi;B.Sieklucka;A.Bhattacharjee;T.Hashiguchi
• 通讯作者: T.Hashiguchi