Domain imaging across the magneto-structural phase transitions in Fe1+yTe
Domain imaging across the magneto-structural phase transitions in Fe1+yTe
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DOI：
10.1038/s41535-018-0096-1
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发表时间：
2017-11
影响因子：
5.7
通讯作者：
J. Warmuth;M. Bremholm;P. Hofmann;J. Wiebe;R. Wiesendanger
中科院分区：
文献类型：
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作者：
J. Warmuth;M. Bremholm;P. Hofmann;J. Wiebe;R. Wiesendanger
研究铁基超导体母体化合物的磁相变对于理解相关超导化合物中的配对机制是必不可少的。尽管这些材料的化学和电子性质在纳米尺度上通常是强烈不均匀的，但使用空间分辨实验技术对磁相变的研究仍然很少。在这里，我们提出了一个真实的空间自旋分辨扫描隧道显微镜调查的表面的Fe 1+ yTe单晶与不同的过量Fe含量，y，这是连续驱动通过磁相变。对于Fe 1.08 Te，转变成低温单斜相是伴随着由于单斜晶格的四个90旋转域的人字形图案的结构有序的外观。每个结构畴包含局部相称的纳米级对角双条纹反铁磁自旋有序畴与π-相位滑移横过畴界。在低温阶段的Fe 1.12 Te，另一方面，人字形图案变得相当狭窄，不太明确，和一个额外的90旋转组件的自旋顺序与本地元格秩序出现。我们在这里展示的自旋和结构有序的同时成像提供了对Fe 1+ y Te在三临界点附近的磁结构域的性质的有价值的见解，这可能会增加对相关Fe 1+ y Te x Se 1− x材料中超导性机制的理解。
The investigation of the magnetic phase transitions in the parent compounds of Fe-based superconductors is regarded essential for an understanding of the pairing mechanism in the related superconducting compounds. Even though the chemical and electronic properties of these materials are often strongly inhomogeneous on a nanometer length scale, studies of the magnetic phase transitions using spatially resolved experimental techniques are still scarce. Here, we present a real space spin-resolved scanning tunneling microscopy investigation of the surface of Fe 1+ y Te single crystals with different excess Fe content, y, which are continuously driven through the magnetic phase transition. For Fe 1.08 Te, the transition into the low-temperature monoclinic phase is accompanied by the appearance of a chevron-patterned structural ordering due to the four 90 rotational domains of the monoclinic lattice. Each of the structural domains contains locally commensurate nanoscale diagonal double stripe antiferromagnetic spin order domains with π-phase slips accross domain boundaries. In the low-temperature phase of Fe 1.12 Te, on the other hand, the chevron pattern gets rather narrow and less well-defined, and an additional 90 rotated component of the spin-order with local plaquette order emerges. The simultaneous imaging of spin and structural order we show here gives valuable insights into the nature of the magneto-structural domains of Fe 1+ y Te near the tricritical point, which presumably add to the understanding of the mechanism of superconductivity in the related Fe 1+ y Te x Se 1− x material.