Magnetic correlations in the extended kagome YBaCo4O7 probed by single-crystal neutron scattering.
Magnetic correlations in the extended kagome YBaCo4O7 probed by single-crystal neutron scattering.
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DOI：
10.1103/physrevlett.103.037202
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发表时间：
2009-04
影响因子：
8.6
通讯作者：
P. Manuel;L. Chapon;P. Radaelli;Hong Zheng;J. Mitchell
中科院分区：
文献类型：
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作者：
P. Manuel;L. Chapon;P. Radaelli;Hong Zheng;J. Mitchell
我们研究了阻挫系统YBaCo_4 O_（7.0），通常被描述为在三角晶格上磁性离子的kagome层和三角层的交替堆叠，通过单晶中子衍射实验高于Néel有序转变。实验数据显示明显的磁漫散射，这是成功地模拟直接蒙特卡罗模拟。长程磁相关被发现沿着的c轴，由于角共享双金字塔的存在下，在有限的温度下创建准一维秩序。相反，在可果美层（ab平面）中，自旋-自旋相关函数，显示短程120度配置，快速衰减，通常在自旋液体中发现。YBaCo_4 O_7在实验上实现了一类新的二维阻挫系统，其中强的面外耦合并不解除面内简并，而是作为一个外部“场”。"
We have studied the frustrated system YBaCo4O7.0 generally described as an alternating stacking of kagome and triangular layers of magnetic ions on a trigonal lattice, by single-crystal neutron diffraction experiments above the Néel ordering transition. Experimental data reveal pronounced magnetic diffuse scattering, which is successfully modeled by direct Monte Carlo simulations. Long-range magnetic correlations are found along the c axis, due to the presence of corner-sharing bipyramids, creating quasi-one-dimensional order at finite temperature. In contrast, in the kagome layers (ab plane), the spin-spin correlation function, displaying a short-range 120 degrees configuration, decays rapidly as typically found in spin liquids. YBaCo4O7 experimentally realizes a new class of two-dimensional frustrated systems where the strong out-of-plane coupling does not lift the in-plane degeneracy, but instead acts as an external "field."