Ferromagnetism in van der Waals compound MnSb1.8Bi0.2Te4
Ferromagnetism in van der Waals compound MnSb1.8Bi0.2Te4
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DOI：
10.1103/physrevmaterials.4.064411
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发表时间：
2020-06-11
影响因子：
3.4
通讯作者：
Ratcliff, William, II
中科院分区：
文献类型：
--
作者：
Chen, Yangyang;Chuang, Ya-Wen;Ratcliff, William, II
拓扑学和磁学的交叉点代表了发现新的量子现象和器件概念的新天地。在这项工作中，我们表明，在一定的合成条件下，一个货车德瓦耳斯单晶化合物MnSb 1.8Bi 0.2Te 4表现出净铁磁态的居里温度为26 K，在之前观察到的完全补偿反铁磁顺序的Mn（Sb，Bi）（2）Te-4家庭的其他成员。我们采用磁输运，体磁化，X射线和中子散射的研究，以说明结构，磁性和电气性能的MnSb1.8Bi0.2Te4。我们的结构分析揭示了相当大的Mn-Sb位点混合，并提出了最近提出的机制，其中Mn占据Sb位点介导Mn层之间的铁磁耦合[Murakami等人，物理评论B 100，195103（2019）]，可能在发挥作用。与反铁磁化合物MnSb2Te4进行的密切比较说明了系统的微妙磁相互作用和局部化学所起的重要作用。MnSb1.8Bi0.2Te4在低温下出现异常的霍尔效应，这暗示了与该家族其他成员不同的磁基态。我们的结果是一个重要的一步，在合成和理解材料的磁性与拓扑特性。
The intersection of topology and magnetism represents a new playground to discover novel quantum phenomena and device concepts. In this work, we show that under certain synthetic conditions, a van der Waals single-crystalline compound MnSb1.8Bi0.2Te4 exhibits a net ferromagnetic state with a Curie temperature of 26 K, in contrast to the fully compensated antiferromagnetic order observed previously for other members of the Mn(Sb, Bi)(2)Te-4 family. We employ magneto-transport, bulk magnetization, x-ray and neutron scattering studies to illustrate the structural, magnetic, and electrical properties of MnSb1.8Bi0.2Te4. Our structural analyses reveal considerable Mn-Sb site mixing and suggest a recently proposed mechanism, where Mn occupying the Sb site mediates a ferromagnetic coupling between Mn layers [Murakami et al., Phys. Rev. B 100, 195103 (2019)], could be at play. Close comparisons made to an antiferromagnetic compound MnSb2Te4 illustrate the subtle magnetic interactions of the system and the important role played by local chemistry. The appearance of an unusual anomalous Hall effect in MnSb1.8Bi0.2Te4 at low temperatures hints at a magnetic ground state different from other members of this family. Our results are an important step in the synthesis and understanding of magnetism in materials with topological characteristics.