Effect of pressure on single-chain magnets with repeating units of the MnIII-NiII-MnIII trimer
Effect of pressure on single-chain magnets with repeating units of the MnIII-NiII-MnIII trimer
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DOI：
10.1103/physrevb.72.144421
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发表时间：
2005-10
影响因子：
3.7
通讯作者：
M. Mito;H. Deguchi;T. Tajiri;S. Takagi;M. Yamashita;H. Miyasaka
中科院分区：
文献类型：
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作者：
M. Mito;H. Deguchi;T. Tajiri;S. Takagi;M. Yamashita;H. Miyasaka
单链磁体L：Ni II离子的链内配位体；A−1：链间反阴离子(CID：2)是一个具有重复单元的一维铁磁性网络体系，其本身就是一个具有S=3自旋基态和平行于桥联方向的负单轴各向异性(CID：1)D(CID：2)的单分子磁体。在该SCM体系中，磁矩的缓慢弛豫源于自旋反转(CID：1)(CID：1)E(CID：2)的能垒，它与三聚体(CID：1)J三聚体(CID：2)之间的铁磁相互作用以及三聚体的D密切相关。我们通过P=13.5kbar的静水压力下的交流磁化率测量和P=20.0kbar的晶体结构分析实验，研究了压力对代表上述SCM家族的三个化合物的影响，并观察到当J特别增大时，(Cid：1)E明显增大。当J=13.5kbar时，(fi：1)E明显增大。静水压力的施加使(Cd：1)E(Cd：1)在实验的压力区(Cd：2)最大增加了10%。(Cd：1)E的压力依赖关系随L所涉及的配位配体的种类和链内结构的不同而不同，我们实验发现，如果在该体系中连续增加(Cd：1)E，则各向同性晶格收缩是可取的。
The single-chain magnet L: intrachain attaching ligand of Ni II ion; A −1 : interchain counteranion (cid:2) is a ferromagnetic one-dimensional network system with repeating units of the Mn III -Ni II -Mn III trimer which itself behaves as a single-molecule magnet with an S =3 spin ground state and negative uniaxial single-ion anisotropy (cid:1) D (cid:2) parallel to the bridging direction. The slow relaxation of the magnetic moment in this SCM system originates in an energy barrier for spin reversal (cid:1) (cid:1) E (cid:2) , which is closely related to the ferromagnetic interaction between the trimers (cid:1) J trimer (cid:2) as well as to the D of the trimer. We have investigated the effects of pressure on three compounds representative of the above SCM family through ac susceptibility measurements under hydrostatic pressures up to P =13.5 kbar and crystal structural analysis experiments up to P =20.0 kbar, and have observed a pronounced enlargement of (cid:1) E when J was artificially increased. The application of hydrostatic pressure brought about the systematic enhancement of (cid:1) E (cid:1) a maximum increase of 10% within the pressure region of the experiments (cid:2) . The pressure dependence of (cid:1) E varied according to the kind of attaching ligand L involved and the intrachain structure, and we have experimentally found that isotropic lattice shrinkage is desirable if a continuous increase of (cid:1) E in this system is aimed at.