Neutron scattering study of the magnetic structure of Cs2CuCl4
Neutron scattering study of the magnetic structure of Cs2CuCl4
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DOI：
10.1088/0953-8984/8/40/012
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发表时间：
1996-09-30
影响因子：
2.7
通讯作者：
Tylczynski, Z
中科院分区：
文献类型：
--
作者：
Coldea, R;Tennant, DA;Tylczynski, Z
用弹性中子散射测量了近一维海森堡反铁磁体Cs_2CuCl_4有序相的磁结构。Cs2CuCl 4在正交Pnma空间群中结晶，其中Cu 2+自旋链沿着晶体学b方向运行。在有序化温度T-N = 0.62 +/-0.01 K以下，磁结构沿链方向沿着不对称，有序化波矢q =（0，0.472，0）（rlu）与温度无关。无公度结构的发生被证明是由链之间的交换相互作用引起的自旋上的挫折的后果。群论用于确定与晶体对称性相容的可能的磁结构。结果表明，在T = 0.3 K时，自旋有序是摆线的，自旋在包含传播方向B的平面内旋转.平均场计算的磁基态能量包括交换各向异性效应被用来研究所观察到的结构的稳定性。提出了与磁结构特征相一致的链间交换常数的值。
The magnetic structure in the ordered phase of the nearly one-dimensional Heisenberg antiferromagnet Cs2CuCl4 has been measured using elastic neutron scattering. Cs2CuCl4 crystallizes in the orthorhombic Pnma space group with Cu2+ spin chains running along the crystallographic b-direction. Below the ordering temperature T-N = 0.62 +/- 0.01 K the magnetic structure is incommensurate along the chain direction with a temperature-independent ordering wavevector q = (0, 0.472, 0) (rlu). The occurrence of an incommensurate structure is shown to be the consequence of frustration on the spins induced by the exchange interaction between chains. Group theory is used to determine the possible magnetic structures compatible with the symmetry of the crystal. The results show that at T = 0.3 K the spin ordering is cycloidal with spins rotating in a plane that contains the propagation direction b. A mean-field calculation of the magnetic ground-state energy including exchange anisotropy effects is used to study the stability of the observed structure. Values for the interchain exchange constants that are consistent with the features of the magnetic structure are proposed.