A density functional theory study of the electronic structures and magnetic properties of Fe_((1-x))Co_x alloy nanowires encapsulated in (10,0) carbon nanotubes  

作　　者：解忧 张建民 

机构地区：[1]College of Physics and Information Technology,Shaanxi Normal University [2]College of Science,Xi'an University of Science and Technology

出　　处：《Chinese Physics B》2011年第12期378-384,共7页中国物理B（英文版）

基　　金：Project supported by the State Key Development for Basic Research of China (Grant No. 2010CB631002);the National Natural Science Foundation of China (Grant No. 51071098)

摘　　要：Under the generalized gradient approximation, the electronic structures and magnetic properties of Fe（1-x）Cox alloy nanowires encapsulated inside zigzag （10,0） carbon nanotubes （CNTs） are investigated systematically using firstprinciple density functional theory calculations. For the fully relaxed Fe（1-x）Cox/CNT structures, all the C atoms relax outwards, and thus the diameters of the CNTs are slightly increased. Formation energy analysis shows that the combining processes of all Fe（1-x）Cox/CNT systems are exothermic, and therefore the Fe（1-x）Cox alloy nanowires can be encapsulated into semiconducting zigzag （10,0） CNTs and form stable hybrid structures. The charges are transferred from the Fe（1-x）Cos nanowires to the more electronegative CNTs, and the Fe-C/Co-C bonds formed have polar covalent bond characteristics. Both the spin polarization and total magnetic moment of the Fe（1-x）Cox/CNT system are smaller than those of the corresponding freestanding Fe（1-x）Cox nanowire, and the magnetic moment of the Fe（1-x）Cox/CNT system decreases monotonously with increasing Co concentration, but the Fe（1-x）Cox/CNT systems still have a large magnetic moment, implying that they can be utilized in high-density magnetic recording devices.Under the generalized gradient approximation, the electronic structures and magnetic properties of Fe（1-x）Cox alloy nanowires encapsulated inside zigzag （10,0） carbon nanotubes （CNTs） are investigated systematically using firstprinciple density functional theory calculations. For the fully relaxed Fe（1-x）Cox/CNT structures, all the C atoms relax outwards, and thus the diameters of the CNTs are slightly increased. Formation energy analysis shows that the combining processes of all Fe（1-x）Cox/CNT systems are exothermic, and therefore the Fe（1-x）Cox alloy nanowires can be encapsulated into semiconducting zigzag （10,0） CNTs and form stable hybrid structures. The charges are transferred from the Fe（1-x）Cos nanowires to the more electronegative CNTs, and the Fe-C/Co-C bonds formed have polar covalent bond characteristics. Both the spin polarization and total magnetic moment of the Fe（1-x）Cox/CNT system are smaller than those of the corresponding freestanding Fe（1-x）Cox nanowire, and the magnetic moment of the Fe（1-x）Cox/CNT system decreases monotonously with increasing Co concentration, but the Fe（1-x）Cox/CNT systems still have a large magnetic moment, implying that they can be utilized in high-density magnetic recording devices.

关 键 词：Fe-Co alloy carbon nanotube electronic structure magnetic property 

分 类 号：O488[理学—固体物理]