机构地区:[1]School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China [2]Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China [3]State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics,Tsinghua University,Beijing 100084,China [4]Beijing Key Laboratory of Energy Conversion and Storage Materials,College of Chemistry,Beijing Normal University,Beijing 100875,China [5]Department of Chemistry and Chemical Biology,Rutgers University,Piscataway 08854,USA [6]Tsinghua-Foxconn Nanotechnology Research Center,Tsinghua University,Beijing 100084,China [7]Frontier Science Center for Quantum Information,Beijing 100084,China
出 处:《Science China Materials》2022年第2期477-485,共9页中国科学(材料科学(英文版)
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。
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.
关 键 词:MnSb2Te4 crystal growth glassy magnetic ground state anomalous Hall effect
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