Materials Science and Technology Division, Oak Ridge National Laboratory, Tennessee 37831, USA.
Phys Rev Lett. 2012 Aug 17;109(7):077003. doi: 10.1103/PhysRevLett.109.077003. Epub 2012 Aug 16.
The relationship between vacancy ordering and magnetism in TlFe(1.6)Se(2) has been investigated via single crystal neutron diffraction, nuclear forward scattering, and transmission electron microscopy. The examination of chemically and structurally homogeneous crystals allows the true ground state to be revealed, which is characterized by Fe moments lying in the ab plane below 100 K. This is in sharp contrast to crystals containing regions of order and disorder, where a competition between c axis and ab plane orientations of the moments is observed. The properties of partially disordered TlFe(1.6)Se(2) are, therefore, not associated with solely the ordered or disordered regions. This contrasts the viewpoint that phase separation results in independent physical properties in intercalated iron selenides, suggesting a coupling between ordered and disordered regions may play an important role in the superconducting analogues.
通过单晶中子衍射、核前向散射和透射电子显微镜研究了 TlFe(1.6)Se(2)中的空位有序和磁性之间的关系。对化学和结构均匀的晶体的研究可以揭示真实的基态，其特征是 Fe 磁矩在低于 100 K 时位于 ab 平面内。这与包含有序和无序区域的晶体形成鲜明对比，在后者中观察到磁矩在 c 轴和 ab 平面方向之间的竞争。因此，部分无序 TlFe(1.6)Se(2)的性质与有序或无序区域无关。这与相分离导致插层铁硒化物具有独立物理性质的观点相反，表明有序和无序区域之间的耦合可能在超导类似物中发挥重要作用。
