The NOR observation of Spin-Peierls transition in an antiferromagnetic MX-chain complex [NiBr(chxn) 2]Br2
The NOR observation of Spin-Peierls transition in an antiferromagnetic MX-chain complex [NiBr(chxn) 2]Br2
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DOI：
10.1021/ja039857x
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发表时间：
2004-02-18
影响因子：
15
通讯作者：
Ikeda, R
中科院分区：
文献类型：
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作者：
Takaishi, S;Tobu, Y;Ikeda, R
在anS=1/ 21维Heisenberg反铁磁金属配合物[NiBr(chxn)2]Br2（chxn: 1R， 2r -二氨基环己烷）中进行了核四极共振（NQR）测量，该配合物具有卤素桥接的MX链结构−Br−Ni3+−Br−Ni3+−Br−。在40 K以下观察到两个81br NQR信号，而在130 K以上观察到单个信号，表明在40 K以下存在两个非等效桥接Br位点。这个NQR结果与先前报道的磁化率和x射线结果一起表明，在40和130 K之间发生了向自旋佩尔斯态的转变。这篇通讯报道了金属配合物中的第一个自旋-佩尔斯跃迁，其中纯d电子对磁性有贡献。此外，我们还展示了一种新的实验方法来研究自旋-佩尔斯系统。
81Br Nuclear quadrupole resonance (NQR) measurement was performed in anS=1/2one-dimensional Heisenberg antiferromagnetic metal complex [NiBr(chxn)2]Br2(chxn: 1R,2R-diaminocyclohexane), having a halogen-bridged MX chain structure −Br−Ni3+−Br−Ni3+−Br−. Two81Br NQR signals were observed below 40 K, while a single signal was observed above 130 K, showing the presence of two nonequivalent bridging Br sites below 40 K. This NQR result together with previously reported magnetic susceptibility and X-ray results indicate the occurrence of a transition into a spin-Peierls state between 40 and 130 K. This communication reports the first spin-Peierls transition in metal complexes in which pure d electrons contribute to the magnetism. In addition, we demonstrated a new experimental method for studying a spin-Peierls system.