Ab initio studies of isolated hydrogen vacancies in graphane

作者：Mapasha R E^*; Molepo M P; Chetty N

来源：Physica E: Low-Dimensional Systems and Nanostructures , 2016, 79: 52-58.

DOI：10.1016/j.physe.2015.12.014

• Vacancies
• Sublattice
• Density functional theory
• Charge state
• Magnetic moment

We present a density functional study of various hydrogen vacancies located on a single hexagonal ring of graphane (fully hydrogenated graphene) considering the effects of charge states and the position of the Fermi level. We find that uncharged vacancies that lead to a carbon sublattice balance are energetically favorable and are wide band gap systems just like pristine graphane. Vacancies that do create a sublattice imbalance introduce spin polarized states into the band gap, and exhibit a half-metallic behavior with a magnetic moment of 1.00 mu B per vacancy. The results show the possibility of using vacancies in graphane for novel spin-based applications. When charging such vacancy configurations, the deep donor (+1/0) and deep acceptor (0/-1) transition levels within the band gap are noted. We also note a half-metallic to metallic transition and a significant reduction of the induced magnetic moment due to both negative and positive charge doping.

• 出版日期2016-5