磁性超卤素对二维硅烯电磁性质的调控

  • 格式:pdf
  • 大小:44.69 KB
  • 文档页数:1

磁性超卤素对二维硅烯电磁性质的调控
赵天山,张顺洪,王前*
北京大学应用物理与技术研究中心,北京,100871
*Email: qianwang2@pku.edu.cn

卤族(halogen)元素, 包括氟(F)、氯(Cl)、溴(Br)、碘(I)和砹(At), 具有高的电子亲和能(EA)与强反应活性
及氧化性。它们在材料合成与改性方面的广泛应用极大地激励人们研究超卤素(superhalogen), 即EA 比卤素
原子的EA(3.0~3.6 eV)更高的一类基团或分子。与卤素原子相比, 超卤素表现出电负性更大、结构更丰富、
性质更新颖等更加丰富的特征。目前还未见利用超卤素来修饰材料的研究报道。应用密度泛函理论,我们
系统研究了实验上合成的磁性超卤素(MnCl
3
)对硅烯的表面修饰及其所引起的物理化学特性的变化。我们

发现超卤素的表面覆盖浓度、吸附构型能有效地调控硅稀的电子结构和磁特性。体系可由半导体变为半金
属,由非磁体系变为铁磁或反铁磁体系,从而表现出丰富的物理化学特征。

关键词:超卤素;硅烯;表面修饰;二维材料;磁性
参考文献
(1) Wu, M. M.; Wang, H.; Ko, Y. J.; Wang, Q.; Sun, Q.; Kiran, B.; Kandalam, A. K.; Bowen, K. H.; Jena, P.
Angew Chem Int Ed 2011, 50, 2568.

Tuning Electronic and Magnetic Properties of Silicene with Magnetic
Superhalogens

Tianshan Zhao, Shunhong Zhang, Qian Wang*
Center for Applied Physics and Technology, College of Engineering, Peking University, Beijing
100871, China

Due to its compatibility with the well-developed Si-based semiconductor industry, silicene has attracted
considerable attention. Using density functional theory we show for the first time that recently synthesized
superhalogen MnCl3 can be used to tune the electronic and magnetic properties of silicene, from semi-metallic to
semiconducting with a wide range of band gaps, as well as from nonmagnetic to ferromagnetic (or
antiferromagnetic) by changing the coverage of the superhalogen molecules. The electronic properties can be
further modulated when a superhalogen and a halogen are used synergistically. The present study indicates that
because of large electron affinity and rich structural diversity superhalogen molecules have advantages over the
conventional halogen atoms in modulating material properties of silicene.