Two-dimensional bipolar magnetic semiconductors with high Curie-temperature and electrically controllable spin polarization realized in exfoliated Cr(pyrazine)_(2) monolayers  

作　　者：Xiangyang Li Haifeng Lv Xiaofeng Liu Tong Jin Xiaojun Wu Xingxing Li Jinlong Yang 

机构地区：[1]Hefei National Laboratory of Physical Science at the Microscale,Department of Chemical Physics,Synergetic Innovation Center of Quantum Information&Quantum Physics,University of Science and Technology of China,Hefei,230026,China [2]Department of Chemistry,Key Laboratory of Functional Inorganic Materials of Anhui Province,Anhui University,Hefei,230601,China

出　　处：《Science China Chemistry》2021年第12期2212-2217,共6页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China(21688102);by the National Key Research&Development Program of China(2016YFA0200604);by Anhui Initiative in Quantum Information Technologies(AHY090400);by the Youth Innovation Promotion Association CAS(2019441);by USTC Research Funds of the Double First-Class Initiative(YD2060002011)。

摘　　要：Exploring two-dimensional(2D)magnetic semiconductors with room-temperature magnetic ordering and electrically controllable spin-polarization is a highly desirable but challenging task for nano-spintronics.Here,through first-principles calculations,we propose to realize such a material by exfoliating the recently synthesized organometallic layered crystal Li0.7[Cr(pyz)_(2)]Cl0.7·0.25(THF)(pyz=pyrazine,THF=tetrahydrofuran).The feasibility of exfoliation is confirmed by the rather low exfoliation energy of 0.27 J m^(−2),even smaller than that of graphite.In exfoliated Cr(pyz)_(2)monolayers,each pyrazine ring grabs one electron from the Cr atom to become a radical anion,and then a strong d-p direct-exchange magnetic interaction emerges between Cr cations and pyrazine radicals,resulting in room-temperature ferrimagnetism with a Curie temperature of 342 K.Moreover,the Cr(pyz)_(2)monolayer is revealed to be an intrinsic bipolar magnetic semiconductor where electrical doping can induce half-metallic conduction with controllable spin-polarization direction.

关 键 词：two-dimensional material FERRIMAGNETISM bipolar magnetic semiconductor half metal first principles 

分 类 号：TN304[电子电信—物理电子学] TB383.1[一般工业技术—材料科学与工程]