Coughlin Amanda L, Xie Dongyue, Zhan Xun, Yao Yue, Deng Liangzi, Hewa-Walpitage Heshan, Bontke Trevor, Chu Ching-Wu, Li Yan, Wang Jian, Fertig Herbert A, Zhang Shixiong
Department of Physics, Indiana University, Bloomington, Indiana 47405, United States.
Department of Mechanical and Materials Engineering, University of Nebraska, Lincoln, Nebraska 68588, United States.
Nano Lett. 2021 Nov 24;21(22):9517-9525. doi: 10.1021/acs.nanolett.1c02940. Epub 2021 Nov 3.
The emergence of van der Waals (vdW) magnets has created unprecedented opportunities to manipulate magnetism for advanced spintronics based upon all-vdW heterostructures. Among various vdW magnets, CrTe possesses high temperature ferromagnetism along with possible topological spin textures. As this system can support self-intercalation in the vdW gap, it is crucial to precisely pinpoint the exact intercalation to understand the intrinsic magnetism of the system. Here, we developed an iterative method to determine the self-intercalated structures and show evidence of vdW "superstructures" in individual CrTe nanoplates exhibiting magnetic behaviors distinct from bulk chromium tellurides. Among 26,332 possible configurations, we unambiguously identified the Cr-intercalated structure as 3-fold symmetry broken CrTe segmented by vdW gaps. Moreover, a twisted Cr-intercalated layered structure is observed. The spontaneous formation of twisted vdW "superstructures" not only provides insight into the diverse magnetic properties of intercalated vdW magnets but may also add complementary building blocks to vdW-based spintronics.
范德华（vdW）磁体的出现为基于全vdW异质结构的先进自旋电子学中操控磁性创造了前所未有的机会。在各种vdW磁体中，CrTe具有高温铁磁性以及可能的拓扑自旋纹理。由于该系统能够在vdW间隙中支持自插层，精确确定确切的插层对于理解系统的本征磁性至关重要。在此，我们开发了一种迭代方法来确定自插层结构，并展示了在表现出与块状碲化铬不同磁性行为的单个CrTe纳米板中存在vdW“超结构”的证据。在26332种可能的构型中，我们明确确定Cr插层结构为被vdW间隙分割的具有三重对称性破缺的CrTe。此外，还观察到一种扭曲的Cr插层层状结构。扭曲的vdW“超结构”的自发形成不仅为插层vdW磁体的多样磁性特性提供了见解，还可能为基于vdW的自旋电子学增添互补的构建模块。
