零维到三维结构中三核铜自旋阻挫簇单元的磁构关系和反对称交换

量子自旋液体是最近几年刚被人们证实除铁磁体、反铁磁体之外的第三种磁性类型,因其有望解释高温超导的运行机制、改变计算机硬盘信息存储方式而在物理、材料等领域备受关注。自旋阻挫作为量子自旋液体的最小单元可能是解开量子自旋液体诸多问题的钥匙,所以在磁学、电学研究领域再一次成为人们研究的热点。基于文献报道的三核铜配合物Cu3(μ3-OH)(μ-OPz)3(NO3)2(H2O)2]·CH3OH(1),我们合成了三维金属有机框架配合物{Ag(HOPz)Cu3(μ3-OH)(NO3)3(OPz)2Ag(NO3)]·6H2O}n(2)(HOPz=甲基(2-吡嗪基)酮肟),并从自旋阻挫的角度对二者磁性质进行对比和详细分析。磁化率数据表明自旋间有很强的反铁磁相互作用和反对称交换。通过包含各向同性和反对称交换的哈密顿算符对两者磁学数据进行拟合并研究其磁构关系,所获最佳拟合参数为:配合物1:Jav=-426 cm^-1,g⊥=1.83,g∥=2.00;配合物2:Jav=-401 cm^-1,g⊥=1.85,g∥=2.00。

Magnetostructural Correlation and Antisymmetric Exchange of Spin Frustrated Triangular[Cu3] in Zero-Dimensional and Three-Dimensional Structure

Quantum spin liquids are the third type of magnetism that has just been confirmed in recent years besides ferromagnets and antiferromagnets.They have attracted much attention in the fields of physics and materials because they are expected to explain the mechanism of high temperature superconductors and to change the storage mode of computer hard disk information.Spin frustration,as the smallest unit of quantum spin liquids,may be the key to solve many problems of quantum spin liquids.Based on the reported three-nuclear copper complexes,Cu3(μ3-OH)(μ-OPz)3(NO3)2(H2O)2]·CH3OH(1)(HOPz=methyl(2-pyrazinyl)ketone oxime),we synthesized a three-dimensional metal-organic framework(MOF),{Ag(HOPz)Cu3(μ3-OH)(NO3)3(OPz)2Ag(NO3)]·6H2O]}n(2).Their magnetic properties were analyzed in detail from the perspective of spin frustration by comparison.The magnetic studies indicate that there exists a strong antiferromagnetic interactions between spins and antisymmetric exchanges.The magnetic data are fitted and the magnetostructural correlation is studied by Hamiltonian containing isotropic and antisymmetric exchanges.The best fitting parameters obtained are:Jav=-426 cm^-1,g⊥=1.83,g//=2.00 for 1 and Jav=-401 cm^-1,g⊥=1.85,g//=2.00 for 2.