扶手椅型石墨烯纳米带吸附钛原子链的电子结构和磁性

Electronic structure and magnetic properties of zigzag Ti atomic chains adsorbed armchair graphene nanoribbons

采用基于密度泛函理论的第一性原理方法,研究了扶手椅型石墨烯纳米带(10G、11G、12G和13G)吸附zigzag型Ti原子链的几何结构、电子性质和磁性。结果表明,zigzag型Ti原子链可以稳定吸附在石墨烯纳米带表面。Ti原子链吸附在纳米带的边缘洞位(10G-1、11G-1、12G-1和13G-1)时较为稳定,且稳定程度随着纳米带宽度的增加而增加。Ti原子链吸附在不同宽度石墨烯纳米带的不同位置,呈现不同的电子结构特性。其中,10G-1、10G-2和11G-2的吸附体系表现出半金属特性,其余吸附体系都为金属性质。同时,石墨烯纳米带吸附Ti原子链的体系具有磁性,其磁性主要来源于Ti原子。当Ti原子链吸附在纳米带边缘洞位时,zigzag原子链上A类Ti原子的磁矩总是小于B类Ti原子的磁矩;随着Ti原子链移向纳米带中心,两类Ti原子的磁矩趋于相等。研究结果揭示,通过吸附zigzag型Ti原子链,可以有效调控石墨烯纳米带的电子结构与磁性质。

The geometrical structures,electronic and magnetic properties of zigzag Ti atomic chains adsorption on armchair graphene nanoribbons（AGNR）have been systemically investigated using first-principles calculations.The results show that zigzag Ti atomic chains can be steadily adsorbed on the surface of AGNR.The adsorption systems are relatively stable for the Ti atomic chain on the edge hollow position of nanoribbons（10G-1,11G-1,12G-1,13G-1）,and the stability of adsorption systems increases with the increase of the width of nanoribbons.Theelectronic structure of the adsorption systems are found to depend strongly on the width of the AGNR.There are half-metal character for Ti chains adsorption on 10G-1,10G-2and 11G-2systems and metallic character for other adsorption systems.The adsorption systems have magnetic moments which mainly come from Ti atoms.When the Ti atom chains adsorption on the edge hollow position of nanoribbons,the magnetic moments of TiAatoms are less than that of the TiB.As the position of the Ti atomic chains moving to the middle symmetrical position of the AGNR,the difference of magnetic moments will be decrease between the TiAand TiB atoms.These results indicate that the adsorbed Ti atomic chains can effectively modify the electrical and magnetic properties of graphene nanoribbons.