First-principles Calculations On Magnetism Of ?₁₂ Boron Sheet Nanoribbons

More recently,monolayer boron(boronene),as a new two-dimensional(2D)group IIIA material,has gained broad attention due to its unique properties.Using first-principles,we have discussed the magnetism and electronic structure of line boron nanoribbons(LBNRs).We found that nanoribbons obtained from ?12 sheets are mostly metallic with different widths.The magnetism of LBNRs with different elements saturated became different,which could explain the reason of the magnetism.Studying the properties of boron nanoribbons,we could understand this new kind of nonomaterial easily.In chapter one,we firstly introduced the experimental and theoretical advances in the field of low-dimensional boron materials,which including zero-dimensional boron materials,one-dimensional boron materials,two-dimensional boron materials.Moreover,we introduced the hydrogen storage performance and mechanical properties of boron materials.We hope that we can get different physical characteristics from the study of the boron nanoribbons with different widths.Chapter two,we described the simulation calculation method used in this article.Our first-principles theoretical calculations are based on the density of functional theory.In addition,we introduced the software and simulation code used in this chapter.In chapter three,we briefly introduced the background of boron sheets and boron nanoribbons.We discussed the magnetism and electronic structure of line boron nanoribbons(LBNRs)with different obtained from ?12 sheets.We found that LBNRs have different magnetism with different widths.The magnetism disappears as the width increasing.Besides,we have studied the band structure of LBNRs,which are mostly metallic.We inferred that the magnetism come from the hanging bonds of the LBNRs.In chapter four,the magnetism of LBNRs with different elements saturated became different,which could explain the reason of the magnetism.The boron nanoribbons with one-hydrogen saturated on the line edges are all metallic and have magnetism,while the boron nanoribbons with two-hydrogen saturated don't have magnetism.Moreover,the boron nanoribbons with two-hydrogen saturated become semiconductors when the width is n=2.Besides each edge atom saturated by 1O or 1C with different widths are all metallic.The research suggests the magnetism of LBNRs with different elements saturated become different.The presence of a dangling bond is crucial to the formation of the magnetism of the LBNRs.Chapter five: conclusion and outlook.Through the research could explain the reason of the magnetism.The presence of a dangling bond is crucial to the formation of the magnetism of the LBNRs.We could control the magnetism of the boron nanoribbons with different elements saturated.The BNRs are an important hierarchy of the nanostructures of boron element and supply a low-dimensional material for the potential applications in nanodevices.