锰掺杂浓度和位置对石墨烯磁性的影响  

Effect ofthe manganese doping concentration and site on the magnetism of graphene

作　　者：刘佳佳[1] 雷天民[1] 张玉明[2] 陈得林 郭辉[2] 张志勇[3] 

机构地区：[1]西安电子科技大学先进材料与纳米科技学院,陕西西安710071 [2]西安电子科技大学微电子学院,陕西西安710071 [3]西北大学信息科学与技术学院,陕西西安710069

出　　处：《西安电子科技大学学报》2015年第4期76-80,106,共6页Journal of Xidian University

基　　金：国家科技重大专项资助项目(2011ZX02707)

摘　　要：基于密度泛函理论,计算出锰掺杂石墨烯在不同掺杂浓度及杂质原子占据不同格点位置条件下的总磁矩和电子自旋态密度.计算结果表明:系统的总磁矩随掺杂浓度增加而变大,在相同掺杂浓度条件下,掺杂原子取不同自旋方向时呈现出更强的磁性.同时发现,杂质原子得失电子能力及超胞的总磁矩都与Mn原子占据的格点位置有关,同种晶格掺杂更有利于增强系统的磁性,表明通过改变掺杂条件有可能对石墨烯的磁性进行调控.通过对系统总自旋态密度和分波态密度的分析,显示Mn掺杂石墨烯超胞系统的磁性机制与Mn原子的d态电子和C原子的p态电子的p-d交换关联作用有关.Based on the density functional theory , the total magnetic moment and the density of states of Mn‐doped graphene are calculated in the case of different impurity concentrations and lattice positions . The results show that the total magnetic moment goes up with the increase of doping concentration . Under the condition of the same impurity concentration , the Mn atoms in different spin directions can make the magnetism stronger . Meanwhile , it is found that the ability to gain and lose electrons of impurities , and the magnetic properties of the supercell are associated with the lattice positions occupied by Mn atoms . Doping in the same lattice has an advantage to enhance the magnetism , meaning that the magnetism of graphene can likely be controlled by changing doping conditions . By analyzing the total and partial density of states , it is concluded that the magnetic mechanism of Mn‐doped graphene is relevant to the p‐d exchange correlation function of Mn‐d and C‐p electrons .

关 键 词：石墨烯 磁性 锰掺杂 掺杂浓度 格点位置 

分 类 号：TN3[电子电信—物理电子学]