通过构建或破坏自旋阻挫设计合成分子基磁体

In this research proposal, we plan to tune the magnetic properties by building a new spin frustration system or destroying a known spin frustration to increase the ground state spin.. The study will include: (1) Introducing an additional spin carrier in a spin frustration complex, the spins will be polarized ferromagnetically due to the competition between antiferromagnetic coupling interaction with different J. (2) Introducing a hetero metal ion at the frustrated position in the spin frustration system, the competition between more than two antiferromagnetic coupling will produce an unique nondegenerate ground spin state to obtain ferrimagnet or cluster with high ground state spin. (3) Giving a theoretical method for determine a system to be spin frustration or not.. The overarching goal of this project is (1) to illuminate the magnetic coupling essential in some systems with spin frustration, in which the temperature dependence of magnetic properties only gives the observed (possible fake) coupling mode and (2) to change the antiferromagnetic coupling into polarized ferromagnetic ordering to increase the ground state spin, further increase the blocking temperature of low-dimensional magnets or get ferrimagnets from antiferromagnets.

本项目拟以自旋阻挫体系为研究对象，通过构建阻挫体系或有目的地破坏阻挫体系，改变体系的基态自旋，以实现对分子基磁体性质的调控。. 主要内容包括（1）在完全反铁磁性耦合体系中引入新的耦合离子形成自旋阻挫体系，通过不同途径下的耦合竞争使原有体系中反铁磁耦合的自旋被极化为铁磁有序；（2）在自旋阻挫体系中的阻挫位点引入异核金属离子破坏原阻挫体系获得单一自旋基态化合物或亚铁磁体；（3）给出一种理论上判断自旋阻挫的方法。. 意义和目的：（1）一些磁性测试数据比如XmT-T图只能给出表观的但错误的耦合结果，而本项目的研究可以揭示这些体系中磁耦合本质；（2）改变反铁磁耦合的自旋为极化铁磁有序后可以提高基态自旋值，进而提高低维磁体的阻塞温度，或得到亚铁磁体。