摘要
As a sister compound of MnBi_(2)Te_(4),the highquality MnSb_(2)Te_(4) single crystals are grown via solid-state reaction where prolonged annealing and narrow temperature window play critical roles on account of its thermal metastability.Single-crystal X-ray diffraction(SCXRD)analysis on MnSb_(2)Te_(4) illustrates a crystal model that is isostructural to MnBi_(2)Te_(4),consisting of Te-Sb-Te-Mn-Te-Sb-Te septuple layers(SLs)stacking in an ABC sequence.However,MnSb_(2)Te_(4) reveals a more pronounced cation intermixing in comparison with MnBi_(2)Te_(4),comprising 28.9(7)%Sb antisite defects on the Mn(3a)site and 19.3(6)%Mn antisite defects on the Sb(6c)site,which may give rise to novel magnetic properties in emerging layered MnBi_(2)Te_(4)-family materials.Unlike the antiferromagnetic(AFM)nature in MnBi_(2)Te_(4),MnSb_(2)Te_(4) exhibits a glassy magnetic ground state below 24 K and can be easily tuned to a ferromagnetic state under a weak applied magnetic field.Its magnetic hysteresis,anisotropy,and relaxation process are investigated in detail via static and dynamic magnetization measurements.Moreover,anomalous Hall effect as a p-type conductor is demonstrated with transport measurements.This work grants MnSb_(2)Te_(4) a possible access to the future exploration of exotic quantum physics by removing the odd/even layer number restraint in realizing quantum transport phenomena in intrinsic AFM MnBi_(2)Te_(4)-family materials,as a result of the crossover between its magnetism and potential topology arising from the Sb-Te layer.
作为MnBi_(2)Te_(4)的姊妹化合物,高质量的MnSb_(2)Te_(4)单晶可以通过固态反应法合成;而由于MnSb_(2)Te_(4)的热亚稳性,长时间的退火和狭窄的退火温区是合成的关键.单晶X射线衍射分析结果说明MnSb_(2)Te_(4)具有与MnBi_(2)Te_(4)类似的晶体结构,由七个原子层的Te-Sb-Te-Mn-Te-SbTe的层状结构单元沿面外方向以ABC顺序堆叠而成.但是,与MnBi_(2)Te_(4)相比,MnSb_(2)Te_(4)显示出更为严重的阳离子互占位,表现为Mn(3a)位上的28.9(7)%Sb反位缺陷和Sb(6c)位上的19.3(6)%的Mn反位缺陷,这种原子分布的变化能够为MnBi_(2)Te_(4)家族材料带来新的磁学特性.与MnBi_(2)Te_(4)的反铁磁性质不同,MnSb_(2)Te_(4)在低于24 K的温度下展现出玻璃磁基态,并且在弱的外加磁场下很容易被诱导至铁磁态.通过静态和动态磁学测量,我们详细研究了MnSb_(2)Te_(4)的磁滞行为、磁各向异性和磁弛豫过程.此外,通过输运测量,我们证明了合成的MnSb_(2)Te_(4)晶体是p型导体,并且能够呈现出反常霍尔效应.MnSb_(2)Te_(4)的不同于MnBi_(2)Te_(4)的磁学特性与Sb-Te层产生的潜在拓扑特性相互作用,有望突破反铁磁MnBi_(2)Te_(4)家族材料中实现量子输运现象的奇数或者偶数的层数限制,为新奇的量子物理学的探索带来新的可能.
作者
Hao Li
Yaoxin Li
Yukun Lian
Weiwei Xie
Ling Chen
Jinsong Zhang
Yang Wu
Shoushan Fan
李昊;李耀鑫;连宇坤;谢韦伟;陈玲;张金松;吴扬;范守善(School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China;Department of Mechanical Engineering,Tsinghua University,Beijing 100084,Chin;State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics,Tsinghua University,Beijing 100084,China;Beijing Key Laboratory of Energy Conversion and Storage Materials,College of Chemistry,Beijing Normal University,Beijing 100875,China;Department of Chemistry and Chemical Biology,Rutgers University,Piscataway 08854,USA;Tsinghua-Foxconn Nanotechnology Research Center,Tsinghua University,Beijing 100084,China;Frontier Science Center for Quantum Information,Beijing 100084,China)
基金
supported by the Basic Science Center Project of the National Natural Science Foundation of China(51788104)
the Ministry of Science and Technology of China(2018YFA0307100)
the National Natural Science Foundation of China(51991340 and 21975140)
supported by the Beckman Young Investigator award。
