Study of quantum magnetism in nano spin polyhedrons

纳米自旋多面体量子磁性研究

• 批准号: 16340107
• 负责人: NOJIRI Hiroyuki
• 金额: $ 10.5万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16340107/
• 关键词: single molecular magnet; high magnetic field; quantum information; magnetism; spin polyhedron; 量子計算; 量子スピン系

Spin polyhedrons are antiferromagnetic spin clusters of high symmetry without disorders. Variety of magnetic networks is possible because a translational symmetry in not needed in such clusters. We have investigated two types of clusters Mo72Fe30 and Fe9. The former cluster is so called corner-sharing network of triangles and latter is the edge-sharing network. The spin frustration is strong and the energy state is highly degenerated.The Mo72Fe30 shows a dip of derivative magnetization at the 1/3 of full magnetization and the origin of dip has been interpreted by the "order by disorder" mechanism. At low temperature, the system shows a broad anomaly in specific heat and in ESR line width. This phenomenon is interpreted as "quasi long range order" caused by the saturation of intra-cluster magnetic correlation. As for the size effect, the smearing of magnetization step is confirmed in Mo72Fe30, where the energy separation among the discrete levels is smaller than the mixing term such as staggered fields and anti-symmetric exchange interaction. On the other hand, clear steps are found in Fe9 and the reduction of the step magnetization is attributed to the asymmetric mixing caused by the spin chirality.The dynamics of the triangle spin ring, which is an important component of spin polyhedrons, has been investigated. A clear adiabatic magnetization and half-step magnetization phenomenon is found. The comparison of magnetization process is made with different systems such as two-nuclear complex and rare earth based cluster. The importance of spin chirality is examined in various system such as spin tube.

自旋多面体是高度对称、无序的反铁磁自旋簇。各种磁网络是可能的，因为在这种簇中不需要平移对称性。我们研究了两种类型的簇 Mo72Fe30 和 Fe9。前一个簇是所谓的三角形角共享网络，后者是边共享网络。自旋挫败很强，能态高度简并。Mo72Fe30在全磁化强度的1/3处表现出导数磁化强度的下降，并且下降的起源可以通过“无序有序”机制来解释。在低温下，系统在比热和 ESR 线宽方面表现出广泛的异常。这种现象被解释为由簇内磁相关饱和引起的“准长程有序”。至于尺寸效应，在Mo72Fe30中证实了磁化步骤的涂抹，其中离散能级之间的能量分离小于混合项，例如交错场和反对称交换相互作用。另一方面，Fe9中发现了明显的阶梯，阶梯磁化强度的降低归因于自旋手性引起的不对称混合。对自旋多面体的重要组成部分三角形自旋环的动力学进行了研究。发现了明显的绝热磁化和半步磁化现象。对二核配合物和稀土基团簇等不同体系的磁化过程进行了比较。自旋手性的重要性在各种系统（例如自旋管）中得到了检验。

项目成果

A heterometal single-molecule magnet of (Mn_2Ni_2Cl_2)-Ni-III-Cl-II(salpa)_2

(Mn_2Ni_2Cl_2)-Ni-III-Cl-II(salpa)_2异质金属单分子磁体

• 发表时间: 2005
• 期刊: J. Am. Chem. Soc. 127
• 作者: Hitoshi;Ohta;Motoi;Kimata;Takahiro;Sakurai;Susumu;Okuho;Yoshiya;Uwatoko;Keiichi;Koyama;Mitsuhiro;Motokawa;Eiji;Ohmichi;Toshihito;Osada;J.Watanabe et al.;T.Kitazawa et al.;F.Mori;Choi KY;H.Nojiri;Yuji Inagaki;Hiroki Oshio
• 通讯作者: Hiroki Oshio

Oximate-bridged trinuclear Dy-Cu-Dy complex behaving as a single-molecule magnet and its mechanistic investigation.

• DOI: 10.1021/ja057183f
• 发表时间: 2006-01
• 期刊: Journal of the American Chemical Society
• 影响因子: 15
• 作者: Fumihito Mori;T. Nyui;T. Ishida;T. Nogami;Kwang-Yong Choi;H. Nojiri

Observation of a half step magnetization in the Cu_3-type triangular spin ring

Cu_3型三角形自旋环半步磁化的观察

• 发表时间: 2006
• 期刊: Phys.Rev.Lett. 96
• 作者: Hitoshi;Ohta;Motoi;Kimata;Takahiro;Sakurai;Susumu;Okuho;Yoshiya;Uwatoko;Keiichi;Koyama;Mitsuhiro;Motokawa;Eiji;Ohmichi;Toshihito;Osada;J.Watanabe et al.;T.Kitazawa et al.;F.Mori;Choi KY
• 通讯作者: Choi KY

Cyano-bridged MnIII3MIII (MIII = Fe, Cr) complexes : Synthesis, structure, and magnetic properties

• DOI: 10.1021/ic0505753
• 发表时间: 2005-07
• 期刊: Inorganic Chemistry
• 影响因子: 4.6
• 作者: H. Miyasaka;Hitomi Takahashi;Tomokura Madanbashi;K. Sugiura;R. Clérac;H. Nojiri

Effect of spin chirality on magnetization in triangular rings

自旋手性对三角环磁化强度的影响

• 发表时间: 2005
• 期刊: PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT 159
• 作者: Hitoshi;Ohta;Motoi;Kimata;Takahiro;Sakurai;Susumu;Okuho;Yoshiya;Uwatoko;Keiichi;Koyama;Mitsuhiro;Motokawa;Eiji;Ohmichi;Toshihito;Osada;J.Watanabe et al.;T.Kitazawa et al.;F.Mori;Choi KY;H.Nojiri;Yuji Inagaki;Hiroki Oshio;Hiroki Oshio;H.Nojiri;H.Nojiri
• 通讯作者: H.Nojiri