Strong coupling of Sm and Fe magnetism in SmFeAsO as revealed by magnetic x-ray scattering
Strong coupling of Sm and Fe magnetism in SmFeAsO as revealed by magnetic x-ray scattering
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DOI：
10.1103/physrevb.84.054419
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发表时间：
2011-08-05
影响因子：
3.7
通讯作者：
Brueckel, Th.
中科院分区：
文献类型：
--
作者：
Nandi, S.;Su, Y.;Brueckel, Th.
采用特定元素的X射线共振和非共振磁散射技术研究了SmFeAsO中Fe和Sm亚晶格的磁结构。在110 ~ 5 K之间，Sm和Fe磁矩分别沿着c和a方向排列，符合相同的磁表示Gamma（5）和相同的传播矢量（101/2）。低于5 K，两个子晶格的磁序改变为不同的磁结构，并且Sm矩在等于化学晶胞的磁晶胞中重新排序。建模的Sm亚晶格的温度依赖性，以及在低于5 K的磁结构的变化，提供了明确的证据，一个令人惊讶的强耦合之间的两个亚晶格，并表示需要包括各向异性交换相互作用模型的SmFeAsO和相关化合物。
The magnetic structures adopted by the Fe and Sm sublattices in SmFeAsO have been investigated using element-specific x-ray resonant and nonresonant magnetic scattering techniques. Between 110 and 5 K, the Sm and Fe moments are aligned along the c and a directions, respectively, according to the same magnetic representation Gamma(5) and the same propagation vector (1 0 1/2). Below 5 K, the magnetic order of both sublattices changes to a different magnetic structure, and the Sm moments reorder in a magnetic unit cell equal to the chemical unit cell. Modeling of the temperature dependence for the Sm sublattice, as well as a change in the magnetic structure below 5 K, provides clear evidence of a surprisingly strong coupling between the two sublattices, and indicates the need to include anisotropic exchange interactions in models of SmFeAsO and related compounds.