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arXiv · 2010.11466

Pressure-tuned intralayer exchange in superlattice-like MnBi2Te4/(Bi2Te3)n topological insulators

Jifeng Shao·Yuntian Liu·Meng Zeng·Jingyuan Li·Xuefeng Wu·Xiao-Ming Ma·Feng Jin·Ruie Lu·Yichen Sun·Mingqiang Gu·Kedong Wang·Wenbin Wu·Liusuo Wu·Chang Liu·Qihang Liu·Yue Zhao
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Abstract

The magnetic structures of MnBi2Te4(Bi2Te3)n can be manipulated by tuning the interlayer coupling via the number of Bi2Te3 spacer layers n, while the intralayer ferromagnetic (FM) exchange coupling is considered too robust to control. By applying hydrostatic pressure up to 3.5 GPa, we discover opposite responses of magnetic properties for n = 1 and 2. MnBi4Te7 stays at A-type antiferromagnetic (AFM) phase with a decreasing N\'eel temperature and an increasing saturation field. In sharp contrast, MnBi6Te10 experiences a phase transition from A-type AFM to a quasi-two-dimensional FM state with a suppressed saturation field under pressure. First-principles calculations reveal the essential role of intralayer exchange coupling from lattice compression in determining these magnetic properties. Such magnetic phase transition is also observed in 20% Sb-doped MnBi6Te10 due to the in-plane lattice compression.

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Jifeng Shao, Yuntian Liu, Meng Zeng, Jingyuan Li, Xuefeng Wu, Xiao-Ming Ma, Feng Jin, Ruie Lu, Yichen Sun, Mingqiang Gu, Kedong Wang, Wenbin Wu, Liusuo Wu, Chang Liu, Qihang Liu, Yue Zhao. 2020-10-22. Pressure-tuned intralayer exchange in superlattice-like MnBi2Te4/(Bi2Te3)n topological insulators. https://doi.org/10.1021/acs.nanolett.1c01874

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