Spin-frustrated trinuclear Cu(II) clusters with mixing of 2(S = 1/2) and S = 3/2 states by antisymmetric exchange. 2. Orbital origin of in-plane Dzialoshinsky-Moriya exchange parameters.
Spin-frustrated trinuclear Cu(II) clusters with mixing of 2(S = 1/2) and S = 3/2 states by antisymmetric exchange. 2. Orbital origin of in-plane Dzialoshinsky-Moriya exchange parameters.
复制标题
自旋受阻三核 Cu(II) 簇，通过反对称交换混合 2(S = 1/2) 和 S = 3/2 态。
DOI：
10.1021/ic701797m
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发表时间：
2008
影响因子：
4.6
通讯作者：
M. I. Belinsky
中科院分区：
文献类型：
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作者：
M. I. Belinsky
考虑了Cu3（II）团簇的面内（Gx, Gy）和面外（Gz） Dzialoshinsky-Moriya （DM）交换参数的微观来源。对于Cu离子基态为d（x2-y2）的体系，在局部各向异性轴zi| （zi||Z）和垂直于分子三角Z轴（zi垂直Z， xi||(- Z)）的情况下，DM交换参数对只有Z分量是有效的（Gz不等于0，G(x,y) = 0）。在Cu离子基态为d（x2-y2）和d（z2）的反铁磁（AFM）簇中，得到了Gx、Gy和Gz DM交换参数与局域磁轨道倾斜度的关系。局域d（x2-y2）轨道的倾斜导致了Gz参数的变化和平面内DM交换相互作用（Gx或/和Gy参数）的出现。Gz和Gx，Gy DM交换参数对倾斜角的依赖关系有本质区别。平面内DM交换耦合（Gx，Gy参数）可以显著超过平面外DM耦合（Gz参数）。非零的Gz和Gx，Gy参数可以是正的也可以是负的。对于基态为d（x2-y2）且DM耦合较强的{Cu3}纳米磁体，该模型通过三聚体CuO4局域基团的局域各向异性轴zi与z垂直位置zi的微小倾斜来解释具有相同值的3个DM交换参数（|Gz| = |Gx| = |Gy|）。具有Cu离子d（z2）基态的AFM Cu3簇与具有单个离子d（x2-y2）基态的AFM系统的倾斜度有显著不同。较大的平面内DM交换参数Gx或/和Gy导致2（S = 1/2）和S = 3/2态的混合以及激发态S = 3/2的零场分裂（ZFS） 2D（DM）。激发态S = 3/2的DM交换对ZFS的贡献2D（DM）与局域磁轨道的倾斜度有显著的相关性。
The microscopic origin of the in-plane (Gx, Gy) and out-of-plane (Gz) Dzialoshinsky-Moriya (DM) exchange parameters is considered for the Cu3(II) clusters. For the systems with the d(x2-y2) ground state of the Cu ions, only Z components of the pair DM exchange parameters are active (Gz not equal to 0, G(x,y) = 0) in the cases of the orientations of the local anisotropy axes zi| (zi||Z) and perpendicular (zi perpendicular Z, xi||(- Z)) to the molecular trigonal Z axis. The dependences of the Gx, Gy, and Gz DM exchange parameters on the tilt of the local magnetic orbitals were obtained for the antiferromagnetic (AFM) clusters with the d(x2-y2) and d(z2) ground state of the Cu ions. The tilt of the local d(x2-y2) orbitals results in the change of the Gz parameter and appearance of the in-plane DM exchange interactions (Gx or/and Gy parameters). The dependence of the Gz and Gx,Gy DM exchange parameters on the tilt angle is essentially different. The in-plane DM exchange coupling (Gx,Gy parameters) can significantly exceed the out-of-plane DM coupling (Gz parameter). The nonzero Gz and Gx,Gy parameters can be positive or negative. For the {Cu3} nanomagnet with the d(x2-y2) ground state and relatively strong DM coupling, the model explains the three DM exchange parameters of the same value (|Gz| = |Gx| = |Gy|) by the small tilt of the local anisotropy axes zi of the CuO4 local groups of the trimer from the positions zi perpendicular Z. The dependence of the DM exchange parameters (Gz, Gx, Gy) on the tilt for the AFM Cu3 clusters with the d(z2) ground states of the Cu ions differs significantly from that for the AFM systems with the ground state d(x2-y2) of the individual ions. Large in-plane DM exchange parameters Gx or/and Gy result in the mixing of the 2(S = 1/2) and S = 3/2 states and zero-field splitting (ZFS) 2D(DM) of the excited S = 3/2 state. The DM exchange contribution 2D(DM) to ZFS of the excited S = 3/2 state possesses the significant dependence on the tilt of the local magnetic orbitals.