Structural, electronic and magnetic properties of manganese doping in the upper layer of bilayer graphene
Structural, electronic and magnetic properties of manganese doping in the upper layer of bilayer graphene
复制标题
双层石墨烯上层锰掺杂的结构、电子和磁性能
DOI：
10.1088/0957-4484/19/20/205708
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发表时间：
2008-05-21
期刊：
影响因子：
3.5
通讯作者：
Zhong, Jianxin
中科院分区：
文献类型：
--
作者：
Mao, Yuliang;Zhong, Jianxin
用第一性原理自旋极化计算方法研究了三维过渡金属Mn掺杂到双层石墨烯上层AB-Beral结构中两个典型位的结构、电子和磁学性质。其中一个掺杂位置位于下层石墨烯的碳六边形中心上方(称为H位)，另一个直接位于下层石墨烯的碳原子的顶部(称为T位)。我们发现，在双层石墨烯中，锰的掺杂增大了层间距。电荷密度分布表明，由于Mn掺杂，石墨烯上下层之间的区域具有明显的共价键特征。在H位掺杂的自旋极化能带结构中，无论是多数自旋还是少数自旋，π和π*带在狄拉克点处都相互分离。在T位掺杂的能带结构中，费米能级位于Dirac点以上，并向大多数自旋和少数自旋的导带移动，使双层石墨烯n掺杂。由于H位掺杂，获得了高达95%的自旋极化。H位和T位掺杂时的局域磁矩分别降至1.76μB和1.88μB，均小于自由态时的5μB。
First-principles spin-polarized calculations have been conducted to investigate the structural, electronic and magnetic properties of 3d transition metal Mn doping into two typical sites in the upper layer of bilayer graphene with the AB Bernal structure. One of the doping sites is above the center of a carbon hexagon of the lower graphene layer (called the H site) and the other is directly on top of a carbon atom of the lower graphene layer (called the T site). We found that Mn doping enlarges the interlayer distance in bilayer graphene. Charge density distribution indicates that the region between the upper and lower graphene layer has apparent covalent-bonding characters due to the Mn doping. In the spin-polarized band structure of H site doping, the π and π* bands separate from each other at the Dirac point both in majority spin and minority spin. In the band structure of T site doping, the Fermi level is located above the Dirac point and moves to the conduction bands in majority spin and minority spin, making the bilayer graphene n doped. A high spin polarization of 95% is achieved due to the H site doping. The local moment of Mn for H and T site doping is reduced to 1.76 μB and 1.88 μB, respectively, which are smaller than the value (5 μB) in the free state.