Studies of magnetic behavior of spin-1/2 frustrated system Hg2Cu2F6S
Studies of magnetic behavior of spin-1/2 frustrated system Hg2Cu2F6S
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DOI：
10.1016/j.jmmm.2006.10.472
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发表时间：
2007-03
影响因子：
2.7
通讯作者：
S. Kawabata;Y. Yasui;Y. Kobayashi;M. Sato;N. Igawa;K. Kakurai
中科院分区：
文献类型：
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作者：
S. Kawabata;Y. Yasui;Y. Kobayashi;M. Sato;N. Igawa;K. Kakurai
用~（19）F-NMR研究了Hg_2Cu_2F_6S烧绿石结构的自旋几何阻挫（s）=1/2体系。还进行了磁化率χ和比热C的测量以及中子结构分析。由χ的温度依赖关系估算出的韦斯温度为100 K左右，表明Cu自旋间的交换作用是反铁磁的.该系统没有表现出晶格畸变，并保持顺磁性，至少，低至2.4K。这表明该系统是一个很好的三维阻挫自旋系统的候选者。随着T的降低，19 F-NMR的Knight位移在1080 K出现一个宽的最大值后减小，表明在低T下观察到的χ随T降低的上升不是本征的。
A geometrically frustrated spin (s)=1/2 system Hg2Cu2F6S with the pyrochlore structure has been studied by19F-NMR. Measurements of the magnetic susceptibility χ and specific heat C and neutron structure analyses have also been carried out. The value of the Weiss temperature estimated from the temperature (T) dependence of χ is found to be ∼100K, indicating that the exchange interaction among the Cu spins is antiferromagnetic. The system does not exhibit a lattice distortion and remains paramagnetic, at least, down to 2.4K. It indicates that the system is a good candidate of 3-dimensional frustrated spin systems. With decreasing T, the Knight shift of the19F-NMR decreases after having a broad maximum at ∼80K, indicating that the upturn of χ observed at low T with decreasing T is not intrinsic.