Layer dependence of stacking order in nonencapsulated few-layer CrI3  

本征铁磁二维材料CrI3层间堆叠结构层数依赖性研究（英文）

作　　者：Kai Guo Bowen Deng Zhen Liu Chaofeng Gao Zhongtai Shi Lei Bi Li Zhang Haipeng Lu Peiheng Zhou Linbo Zhang Yingchun Cheng Bo Peng 郭锴;邓博文;刘镇;高超峰;石钟太;毕磊;张丽;陆海鹏;周佩珩;张林博;程迎春;彭波(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;Key Laboratory of Flexible Electronics&Institute of Advanced Materials,Jiangsu National Synergetic Innovation Center for Advanced Materials,Nanjing Tech University,Nanjing 211816,China;Department of Physics,Broida Hall,University of California Santa Barbara,CA 93106-9530,USA;Key Laboratory of Multi-spectral Absorbing Materials and Structures of Ministry of Education,University of Electronic Science and Technology of China,Chengdu 611731,China)

机构地区：[1]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 [2]Key Laboratory of Flexible Electronics&Institute of Advanced Materials,Jiangsu National Synergetic Innovation Center for Advanced Materials,Nanjing Tech University,Nanjing 211816,China [3]Department of Physics,Broida Hall,University of California Santa Barbara,CA 93106-9530,USA [4]Key Laboratory of Multi-spectral Absorbing Materials and Structures of Ministry of Education,University of Electronic Science and Technology of China,Chengdu 611731,China

出　　处：《Science China Materials》2020年第3期413-420,共8页中国科学（材料科学（英文版）

基　　金：the financial support from the National Natural Science Foundation of China (51602040 and 51872039);the Science and Technology Program of Sichuan (M112018JY0025);the Scientific Research Foundation for New Teachers of UESTC (A03013023601007)

摘　　要：Long-range magnetic orders in atomically thin ferromagnetic CrI3 trigger new fascinating physics and application perspectives.The physical properties of two-dimensional(2D)ferromagnetism CrI3 are significantly influenced by interlayer spacing and stacking order,which are sensitive to the hydrostatic pressure and external environments.However,there remains debate on the stacking order at low temperature.Here,we study the interlayer coupling and stacking order of non-encapsulated 2–5 layer and bulk CrI3 at 10 K by Raman spectroscopy;demonstrate a rhombohedral stacking in both antiferromagnetic and ferromagnetic CrI3.The opposite helicity dependence of Ag and Eg modes arising from phonon symmetry further validates the rhombohedral stacking.An anomalous temperature-dependent behavior is observed due to spin-phonon coupling below 60 K.Our study provides insights into the interlayer coupling and stacking orders of 2D ferromagnetic materials.二维体系中的长程铁磁序现象再次打破了Mermin-Wagner理论.铁磁二维材料的铁磁性与层层堆叠的顺序、结构、层间距息息相关.目前对铁磁二维材料CrI3在低温下的堆叠顺序和结构仍不确定,且未见报道.针对该科学问题,本工作深入研究了2–5层及块体CrI3的拉曼特征,详细研究了拉曼特征峰与层数、偏振、旋光和温度之间的依赖关系;揭示了2–5层及块体CrI3在低温下(10 K)为菱方堆叠结构,解决了领域内关于CrI3低温结构的争议,填补了该领域的研究空白,并发现了自旋声子耦合现象.本工作开创了独特的磁光电原位传输测量系统,从样品制备到表征完全与空气隔绝,避免样品污染和损坏,因此,本工作更准确地表征出了CrI3最本征的结构特性.

关 键 词：ferromagnetic 2D materials Ising ferromagnet SPINTRONICS MAGNETO-OPTICAL 

分 类 号：O614.611[理学—无机化学]