Liu Zhen, Guo Yongzheng, Chen Zhiyong, Gong Tao, Li Yue, Niu Yuting, Cheng Yingchun, Lu Haipeng, Deng Longjiang, Peng Bo
National Engineering Research Center of Electromagnetic Radiation Control Materials, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China.
State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 611731, China.
Nanophotonics. 2022 Aug 19;11(19):4409-4417. doi: 10.1515/nanoph-2022-0246. eCollection 2022 Sep.
Intrinsic structural phase is a crucial foundation for the fundamental physical properties, and for creating innovative devices with unprecedented performances and unique functionalities. Long-range ferromagnetic orders of van der Waals CrI are strongly tied with interlayer stacking orders. However, the intrinsic structure of few-layer CrI still remains elusive; the predicted monoclinic phase has not yet been experimentally detected in bare few-layer CrI. Here we uncover the intrinsic structure of few-layer CrI with interlayer antiferromagnetic coupling, which unambiguously show monoclinic stacking in both bare and hBN-encapsulated bilayer and tri-five-layer CrI throughout an entire temperature range from 300 to 10 K. An exotic spring damping effect from hBN encapsulation layers is experimentally observed in hBN/CrI/hBN heterostructures, which partly hinders interlayer sliding of CrI. This work demonstrates the intrinsic monoclinic crystal phase of few-layer CrI and associated correlation with magnetic orders, opening up numerous opportunities for creating magnetic texture by stacking design.
本征结构相是基本物理性质的关键基础，也是创造具有前所未有的性能和独特功能的创新器件的关键基础。范德华CrI的长程铁磁序与层间堆叠顺序紧密相关。然而，少层CrI的本征结构仍然难以捉摸；预测的单斜相尚未在裸少层CrI中通过实验检测到。在这里，我们揭示了具有层间反铁磁耦合的少层CrI的本征结构，明确显示在从300到10 K的整个温度范围内，裸的和hBN封装的双层以及三到五层CrI中均为单斜堆叠。在hBN/CrI/hBN异质结构中通过实验观察到来自hBN封装层的奇异弹簧阻尼效应，这部分地阻碍了CrI的层间滑动。这项工作证明了少层CrI的本征单斜晶相以及与磁序的相关关系，为通过堆叠设计创造磁纹理开辟了众多机会。
