氰根桥连4f-3d低维分子磁体的磁弛豫性能调控研究

发布时间：2018-04-10 01:08

  本文选题：氰根桥连化合物　切入点：二氰胺　出处：《湖北大学》2016年硕士论文

【摘要】：本论文主要研究了氰根桥连4f-3d配位聚合物,特别是基于第二配体N-羟乙基-2-吡咯烷酮的低维分子磁体的磁弛豫性能调控研究。另外还进行了过渡金属和二氰胺体系的结构和磁性研究。主要研究内容如下：1.以1-(2-hydroxyethyl)-2-pyrrolidone(hep)作为辅助配体,K3[Fe(CN)6]或K3[Co(CN)6]作为短桥配体,用溶液挥发法和稀土金属离子(Ln=Y3+,Dy3+,Tb3+,Er3+, Gd3+,Eu3+)组装合成了12种同构型异双核3d-4f氰根桥连配合物,并对1YFe.2DyFe和8DyCo配合物进行了磁性的表征和研究。磁性分析表明,配合物1YFe中金属离子间存在微不足道的磁耦合,配合物2DyFe中金属离子间存在反铁磁相互作用,以及配合物8DyCo中金属离子间传递的弱铁磁耦合。当引入外加直流场时,配合物1YFe和8DyCo均表现出缓慢的磁弛豫行为,而配合物2DyFe表现出单分子磁体性能。2.以吡啶氮氧化物类(3-Picoline N-oxide,2-Picoline N-oxide,Pyridine N-oxide)作为辅助配体,K3[Fe(CN)6]作为桥连配体,用溶液挥发法和稀土金属离子(Ln=Y3+,Dy3+,Tb3+, Er3+,Gd3+,Eu3+)组装合成了6种异金属3d-4f氰根桥连配合物,包含同构型的异双核配合物13YFe-14DyFe,以及简单的一维链状配合物15YFe-18DyFe。磁学研究表明,配合物16DyFe中链内DyⅢ和FeⅢ离子之间通过氰根桥可能传递的是反铁磁耦合。3.以Na[N(CN)2](dca)作为桥连配体,hep或吡啶氮氧化物类(4-Picoline N-oxide, 3-Picoline N-ocide,2-Picoline N-oxide,Pyridine N-oxide)作为辅助配体,用溶液挥发法和过渡金属离子(M=co2+,Mn2+,Ni2+)组装合成了8种多样结构的配合物。配合物19Co和20Ni是同构型的交错双链结构,配合物21Co、22Ni和24Co是三维网状结构,配合物23Mn.25Co和26Co是一维链状结构。磁学研究表明,配合物19Co存在有意义的缓慢磁弛豫行为。
[Abstract]:In this paper, the magnetic relaxation properties of cyanogen bridged 4f-3d coordination polymers, especially the low-dimensional molecular magnets based on the second ligand N-hydroxyethyl-2-pyrrolidone, were studied.The structure and magnetic properties of transition metal and dicyandiamide system were also studied.The main research contents are as follows: 1.The magnetic properties of 1YFe.2DyFe and 8DyCo complexes were investigated.Magnetic analysis shows that there are insignificant magnetic coupling between metal ions in 1YFe, antiferromagnetic interaction among metal ions in 2DyFe, and weak ferromagnetic coupling between metal ions in 8DyCo.The complex 1YFe and 8DyCo exhibit slow magnetic relaxation behavior, while the complex 2DyFe exhibits monolayer magnets with the addition of DC field.The isomorphic heterogeneous binuclear complex 13YFe-14DyFe and the simple one-dimensional chain complex 15YFe-18DyFe are found.Magnetic studies show that the antiferromagnetic coupling of Dy 鈪，

本文编号：1728968