Topological magnetic structures in MnGe: Neutron diffraction and symmetry analysis
Topological magnetic structures in MnGe: Neutron diffraction and symmetry analysis
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MnGe 中的拓扑磁结构：中子衍射和对称性分析
DOI：
10.1103/physrevb.107.024410
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发表时间：
2023
影响因子：
3.7
通讯作者：
Pomjakushina E.
中科院分区：
文献类型：
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作者：
Pomjakushin V.;Plokhikh I.;White J. S.;Fujishiro Y.;Kanazawa N.;Tokura Y.;Pomjakushina E.
从新的中子粉末衍射实验手性立方（）磁铁锰锗（MnGe），我们分析了所有可能的晶体衍射允许的磁性超结构，成功地确定从数据。磁结构的无公度传播矢量与[100]立方轴一致，对应于1.8K时约30 Ω的磁周期。几个最大的晶体对称性的磁性结构被发现同样适合的数据，并提出。这些包括分别在多立方或正交3+3和正交3+2维磁超空间群中的拓扑非平凡磁刺猬和“skyrmion”结构，其中任何一个都可能导致拓扑霍尔效应。在空间群中存在的正交畸变所造成的磁有序状态的过渡并不有利于立方磁刺猬结构，并离开正交刺猬和skyrmion模型作为平等的候选人的磁结构。我们还报告了一个相结合的机械化学和固态化学路线，在环境压力和中等温度下合成MnGe，并与传统的高压合成得到的样品进行比较。
From new neutron powder diffraction experiments on the chiral cubic () magnet manganese germanide (MnGe), we analyze all of the possible crystal symmetry-allowed magnetic superstructures that are determined successfully from the data. The incommensurate propagation vectorsof the magnetic structure are found to be aligned with the [100] cubic axes, and correspond to a magnetic periodicity of about 30 Å at 1.8 K. Several maximal crystallographic symmetry magnetic structures are found to fit the data equally well and are presented. These include topologically nontrivial magnetic hedgehog and “skyrmion” structures in multi-cubic or orthorhombic 3+3 and orthorhombic 3+2 dimensional magnetic superspace groups respectively, with either potentially responsible for topological Hall effect. The presence of orthorhombic distortions in the space groupcaused by the transition to the magnetically ordered state does not favor the cubic magnetic hedgehog structure, and leave both orthorhombic hedgehog and skyrmion models as equal candidates for the magnetic structures. We also report on a combined mechanochemical and solid-state chemical route to synthesize MnGe at ambient pressures and moderate temperatures, and compare with samples obtained by the traditional high pressure synthesis.