铁原子吸附联苯烯单层电子结构的第一性原理

First-principles study of Fe atom adsorbed biphenylene monolayer

联苯烯单层由碳原子的四元、六元和八元环组成,具有与石墨烯相似的单原子层结构.2021年5月,Science首次报道了该材料的实验合成,引起了科研工作者的极大关注.基于第一性原理的密度泛函方法,研究了铁原子在联苯烯单层的吸附构型并分析了其电子结构.结构优化、吸附能和分子动力学的计算表明,联苯烯单层的四元环空位是铁原子最稳定的吸附位点,吸附能可达1.56 eV.电子态密度计算表明铁3d电子与碳的2p电子有较强的轨道杂化,同时电荷转移计算显示铁原子向近邻碳原子转移的电荷约为0.73个电子,说明联苯烯单层与吸附的铁原子之间形成了稳定的化学键.另外,铁原子吸附于联苯烯单层后体系显磁性,铁原子上局域磁矩大小约为1.81μB,方向指向面外.因此,本文确认了联苯烯单层是比石墨烯更好的铁原子吸附载体且体系有磁性,这为研究吸附材料的电磁、输运、催化等特性提供了新的平台.

Biphenylene monolayer is composed of four-,six-and eight-membered carbon rings and has a monatomic layer structure similar to graphene.It was synthesized in experiment recently and reported in Science in May 2021,which has attracted considerable attention in the research field of two-dimensional materials.By the density functional method of the first principle,we study the adsorption configuration of Fe atoms on biphenylene monolayer and analyze its electronic structure.The calculation of structural optimization,adsorption energy and molecular dynamics show that the biphenylene monolayer is a good matrix of Fe atoms.For Fe atoms,the hollow site in the four-membered ring of the biphenylene monolayer is the most stable adsorption site,and the adsorption energy can reach 1.56 eV.The calculation of charge transfer and density of states show that a stable bond can be formed between biphenylene monolayer and Fe atoms,and 0.73 electron is transferred from Fe atom to the neighbored carbon atom.After Fe atom being absorbed,biphenylene monolayer is magnetic,and the magnetic moment of Fe atom is about 1.81 μB and points out of the plane.Compared with graphene,biphenylene monolayer adsorbs Fe atoms more stably,which provides a new platform for studying the electromagnetic,transport and catalytic properties of two-dimensional materials with adatoms.