Pressure-Tuned Intralayer Exchange in Superlattice-Like MnBi2Te4/(Bi2Te3)(n) Topological Insulators
Pressure-Tuned Intralayer Exchange in Superlattice-Like MnBi2Te4/(Bi2Te3)(n) Topological Insulators
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类超晶格 MnBi2Te4/(Bi2Te3)n 拓扑绝缘体中压力调节的层内交换
DOI：
10.1021/acs.nanolett.1c01874
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发表时间：
2021
期刊：
影响因子：
10.8
通讯作者：
Zhao Yue
中科院分区：
文献类型：
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作者：
Shao Jifeng;Liu Yuntian;Zeng Meng;Li Jingyuan;Wu Xuefeng;Ma Xiao-Ming;Jin Feng;Lu Ruie;Sun Yichen;Gu Mingqiang;Wang Kedong;Wu Wenbin;Wu Liusuo;Liu Chang;Liu Qihang;Zhao Yue
MnBi2Te4（Bi2Te3）n的磁结构可以通过Bi2Te3间隔层n的数量调节层间耦合来操纵，而层内铁磁（FM）交换耦合被认为太鲁棒而无法控制。通过施加高达3.5GPa的静水压力，我们发现了n = 1和2时磁性的相反响应。MnBi_4Te_7的反铁磁（AFM）相随Ne ′ el温度的降低和饱和场的增加而保持在A型。与此形成鲜明对比的是，MnBi6Te10经历了从A型AFM到准二维FM状态的相变，在压力下具有抑制的饱和场。第一性原理计算揭示了晶格压缩层内交换耦合在确定这些磁性中的重要作用。在20%Sb掺杂的MnBi6Te10中，由于面内晶格压缩，也观察到了这种磁相变。
The magnetic structures of MnBi2Te4(Bi2Te3)ncan be manipulated by tuning the interlayer coupling via the number of Bi2Te3spacer layersn, 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 forn= 1 and 2. MnBi4Te7stays at A-type antiferromagnetic (AFM) phase with a decreasing Néel temperature and an increasing saturation field. In sharp contrast, MnBi6Te10experiences 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 MnBi6Te10because of the in-plane lattice compression.